diff --git a/ai-service-admin/src/App.vue b/ai-service-admin/src/App.vue
index 28e82e1..b6aa613 100644
--- a/ai-service-admin/src/App.vue
+++ b/ai-service-admin/src/App.vue
@@ -42,15 +42,19 @@
       </div>
       <div class="header-right">
         <div class="tenant-selector">
-          <el-select 
-            v-model="currentTenantId" 
-            placeholder="选择租户" 
+          <el-select
+            v-model="currentTenantId"
+            placeholder="选择租户"
             size="default"
+            :loading="loading"
             @change="handleTenantChange"
           >
-            <el-option label="默认租户" value="default" />
-            <el-option label="租户 A" value="tenant_a" />
-            <el-option label="租户 B" value="tenant_b" />
+            <el-option
+              v-for="tenant in tenantList"
+              :key="tenant.id"
+              :label="tenant.name"
+              :value="tenant.id"
+            />
           </el-select>
         </div>
       </div>
@@ -62,15 +66,19 @@
 </template>
 
 <script setup lang="ts">
-import { ref, computed } from 'vue'
+import { ref, computed, onMounted } from 'vue'
 import { useRoute } from 'vue-router'
 import { useTenantStore } from '@/stores/tenant'
+import { getTenantList, type Tenant } from '@/api/tenant'
 import { Odometer, FolderOpened, Cpu, Monitor, Connection, ChatDotSquare } from '@element-plus/icons-vue'
+import { ElMessage } from 'element-plus'
 
 const route = useRoute()
 const tenantStore = useTenantStore()
 
 const currentTenantId = ref(tenantStore.currentTenantId)
+const tenantList = ref<Tenant[]>([])
+const loading = ref(false)
 
 const isActive = (path: string) => {
   return route.path === path || route.path.startsWith(path + '/')
@@ -78,7 +86,47 @@ const isActive = (path: string) => {
 
 const handleTenantChange = (val: string) => {
   tenantStore.setTenant(val)
+  // 刷新页面以加载新租户的数据
+  window.location.reload()
 }
+
+// Validate tenant ID format: name@ash@year
+const isValidTenantId = (tenantId: string): boolean => {
+  return /^[^@]+@ash@\d{4}$/.test(tenantId)
+}
+
+const fetchTenantList = async () => {
+  loading.value = true
+  try {
+    // 检查当前租户ID格式是否有效
+    if (!isValidTenantId(currentTenantId.value)) {
+      console.warn('Invalid tenant ID format, resetting to default:', currentTenantId.value)
+      currentTenantId.value = 'default@ash@2026'
+      tenantStore.setTenant(currentTenantId.value)
+    }
+
+    const response = await getTenantList()
+    tenantList.value = response.tenants || []
+
+    // 如果当前租户不在列表中，默认选择第一个
+    if (tenantList.value.length > 0 && !tenantList.value.find(t => t.id === currentTenantId.value)) {
+      const firstTenant = tenantList.value[0]
+      currentTenantId.value = firstTenant.id
+      tenantStore.setTenant(firstTenant.id)
+    }
+  } catch (error) {
+    ElMessage.error('获取租户列表失败')
+    console.error('Failed to fetch tenant list:', error)
+    // 失败时使用默认租户
+    tenantList.value = [{ id: 'default@ash@2026', name: 'default (2026)' }]
+  } finally {
+    loading.value = false
+  }
+}
+
+onMounted(() => {
+  fetchTenantList()
+})
 </script>
 
 <style scoped>
diff --git a/ai-service-admin/src/api/tenant.ts b/ai-service-admin/src/api/tenant.ts
new file mode 100644
index 0000000..2fce357
--- /dev/null
+++ b/ai-service-admin/src/api/tenant.ts
@@ -0,0 +1,21 @@
+import request from '@/utils/request'
+
+export interface Tenant {
+  id: string
+  name: string
+  displayName: string
+  year: string
+  createdAt: string
+}
+
+export interface TenantListResponse {
+  tenants: Tenant[]
+  total: number
+}
+
+export function getTenantList() {
+  return request<TenantListResponse>({
+    url: '/admin/tenants',
+    method: 'get'
+  })
+}
diff --git a/ai-service-admin/src/stores/tenant.ts b/ai-service-admin/src/stores/tenant.ts
index ede99d4..efce1e8 100644
--- a/ai-service-admin/src/stores/tenant.ts
+++ b/ai-service-admin/src/stores/tenant.ts
@@ -1,8 +1,11 @@
 import { defineStore } from 'pinia'
 
+// Default tenant ID format: name@ash@year
+const DEFAULT_TENANT_ID = 'default@ash@2026'
+
 export const useTenantStore = defineStore('tenant', {
   state: () => ({
-    currentTenantId: localStorage.getItem('X-Tenant-Id') || 'default'
+    currentTenantId: localStorage.getItem('X-Tenant-Id') || DEFAULT_TENANT_ID
   }),
   actions: {
     setTenant(id: string) {
diff --git a/ai-service/app/api/admin/__init__.py b/ai-service/app/api/admin/__init__.py
index 7582480..40b96bb 100644
--- a/ai-service/app/api/admin/__init__.py
+++ b/ai-service/app/api/admin/__init__.py
@@ -9,5 +9,6 @@ from app.api.admin.kb import router as kb_router
 from app.api.admin.llm import router as llm_router
 from app.api.admin.rag import router as rag_router
 from app.api.admin.sessions import router as sessions_router
+from app.api.admin.tenants import router as tenants_router
 
-__all__ = ["dashboard_router", "embedding_router", "kb_router", "llm_router", "rag_router", "sessions_router"]
+__all__ = ["dashboard_router", "embedding_router", "kb_router", "llm_router", "rag_router", "sessions_router", "tenants_router"]
diff --git a/ai-service/app/api/admin/tenants.py b/ai-service/app/api/admin/tenants.py
new file mode 100644
index 0000000..b86fea9
--- /dev/null
+++ b/ai-service/app/api/admin/tenants.py
@@ -0,0 +1,78 @@
+"""
+Tenant management endpoints.
+Provides tenant list and management functionality.
+"""
+
+import logging
+from typing import Annotated
+
+from fastapi import APIRouter, Depends
+from fastapi.responses import JSONResponse
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.database import get_session
+from app.core.exceptions import MissingTenantIdException
+from app.core.middleware import parse_tenant_id
+from app.core.tenant import get_tenant_id
+from app.models import ErrorResponse
+from app.models.entities import Tenant
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/admin/tenants", tags=["Tenants"])
+
+
+def get_current_tenant_id() -> str:
+    """Dependency to get current tenant ID or raise exception."""
+    tenant_id = get_tenant_id()
+    if not tenant_id:
+        raise MissingTenantIdException()
+    return tenant_id
+
+
+@router.get(
+    "",
+    operation_id="listTenants",
+    summary="List all tenants",
+    description="Get a list of all tenants from the system.",
+    responses={
+        200: {"description": "List of tenants"},
+        401: {"description": "Unauthorized", "model": ErrorResponse},
+        403: {"description": "Forbidden", "model": ErrorResponse},
+    },
+)
+async def list_tenants(
+    session: Annotated[AsyncSession, Depends(get_session)],
+) -> JSONResponse:
+    """
+    Get a list of all tenants from the tenants table.
+    Returns tenant ID and display name (first part of tenant_id).
+    """
+    logger.info("Getting all tenants")
+
+    # Get all tenants from tenants table
+    stmt = select(Tenant).order_by(Tenant.created_at.desc())
+    result = await session.execute(stmt)
+    tenants = result.scalars().all()
+
+    # Format tenant list with display name
+    tenant_list = []
+    for tenant in tenants:
+        name, year = parse_tenant_id(tenant.tenant_id)
+        tenant_list.append({
+            "id": tenant.tenant_id,
+            "name": f"{name} ({year})",
+            "displayName": name,
+            "year": year,
+            "createdAt": tenant.created_at.isoformat() if tenant.created_at else None,
+        })
+
+    logger.info(f"Found {len(tenant_list)} tenants: {[t['id'] for t in tenant_list]}")
+
+    return JSONResponse(
+        content={
+            "tenants": tenant_list,
+            "total": len(tenant_list)
+        }
+    )
diff --git a/ai-service/app/core/middleware.py b/ai-service/app/core/middleware.py
index 8e87288..4100813 100644
--- a/ai-service/app/core/middleware.py
+++ b/ai-service/app/core/middleware.py
@@ -4,6 +4,7 @@ Middleware for AI Service.
 """
 
 import logging
+import re
 from typing import Callable
 
 from fastapi import Request, Response, status
@@ -19,11 +20,32 @@ TENANT_ID_HEADER = "X-Tenant-Id"
 ACCEPT_HEADER = "Accept"
 SSE_CONTENT_TYPE = "text/event-stream"
 
+# Tenant ID format: name@ash@year (e.g., szmp@ash@2026)
+TENANT_ID_PATTERN = re.compile(r'^[^@]+@ash@\d{4}$')
+
+
+def validate_tenant_id_format(tenant_id: str) -> bool:
+    """
+    [AC-AISVC-10] Validate tenant ID format: name@ash@year
+    Examples: szmp@ash@2026, abc123@ash@2025
+    """
+    return bool(TENANT_ID_PATTERN.match(tenant_id))
+
+
+def parse_tenant_id(tenant_id: str) -> tuple[str, str]:
+    """
+    [AC-AISVC-10] Parse tenant ID into name and year.
+    Returns: (name, year)
+    """
+    parts = tenant_id.split('@')
+    return parts[0], parts[2]
+
 
 class TenantContextMiddleware(BaseHTTPMiddleware):
     """
     [AC-AISVC-10, AC-AISVC-12] Middleware to extract and validate X-Tenant-Id header.
     Injects tenant context into request state for downstream processing.
+    Validates tenant ID format and auto-creates tenant if not exists.
     """
 
     async def dispatch(self, request: Request, call_next: Callable) -> Response:
@@ -44,10 +66,31 @@ class TenantContextMiddleware(BaseHTTPMiddleware):
                 ).model_dump(exclude_none=True),
             )
 
-        set_tenant_context(tenant_id.strip())
-        request.state.tenant_id = tenant_id.strip()
+        tenant_id = tenant_id.strip()
 
-        logger.info(f"[AC-AISVC-10] Tenant context set: tenant_id={tenant_id.strip()}")
+        # Validate tenant ID format
+        if not validate_tenant_id_format(tenant_id):
+            logger.warning(f"[AC-AISVC-10] Invalid tenant ID format: {tenant_id}")
+            return JSONResponse(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                content=ErrorResponse(
+                    code=ErrorCode.INVALID_TENANT_ID.value,
+                    message="Invalid tenant ID format. Expected: name@ash@year (e.g., szmp@ash@2026)",
+                ).model_dump(exclude_none=True),
+            )
+
+        # Auto-create tenant if not exists (for admin endpoints)
+        if request.url.path.startswith("/admin/") or request.url.path.startswith("/ai/"):
+            try:
+                await self._ensure_tenant_exists(request, tenant_id)
+            except Exception as e:
+                logger.error(f"[AC-AISVC-10] Failed to ensure tenant exists: {e}")
+                # Continue processing even if tenant creation fails
+
+        set_tenant_context(tenant_id)
+        request.state.tenant_id = tenant_id
+
+        logger.info(f"[AC-AISVC-10] Tenant context set: tenant_id={tenant_id}")
 
         try:
             response = await call_next(request)
@@ -56,6 +99,39 @@ class TenantContextMiddleware(BaseHTTPMiddleware):
 
         return response
 
+    async def _ensure_tenant_exists(self, request: Request, tenant_id: str) -> None:
+        """
+        [AC-AISVC-10] Ensure tenant exists in database, create if not.
+        """
+        from sqlalchemy import select
+        from sqlalchemy.ext.asyncio import AsyncSession
+
+        from app.core.database import async_session_maker
+        from app.models.entities import Tenant
+
+        name, year = parse_tenant_id(tenant_id)
+
+        async with async_session_maker() as session:
+            # Check if tenant exists
+            stmt = select(Tenant).where(Tenant.tenant_id == tenant_id)
+            result = await session.execute(stmt)
+            existing_tenant = result.scalar_one_or_none()
+
+            if existing_tenant:
+                logger.debug(f"[AC-AISVC-10] Tenant already exists: {tenant_id}")
+                return
+
+            # Create new tenant
+            new_tenant = Tenant(
+                tenant_id=tenant_id,
+                name=name,
+                year=year,
+            )
+            session.add(new_tenant)
+            await session.commit()
+
+            logger.info(f"[AC-AISVC-10] Auto-created new tenant: {tenant_id} (name={name}, year={year})")
+
 
 def is_sse_request(request: Request) -> bool:
     """
diff --git a/ai-service/app/main.py b/ai-service/app/main.py
index 165e02a..c18afba 100644
--- a/ai-service/app/main.py
+++ b/ai-service/app/main.py
@@ -12,7 +12,8 @@ from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import JSONResponse
 
 from app.api import chat_router, health_router
-from app.api.admin import dashboard_router, embedding_router, kb_router, llm_router, rag_router, sessions_router
+from app.api.admin import dashboard_router, embedding_router, kb_router, llm_router, rag_router, sessions_router, tenants_router
+from app.api.admin.kb_optimized import router as kb_optimized_router
 from app.core.config import get_settings
 from app.core.database import close_db, init_db
 from app.core.exceptions import (
@@ -115,9 +116,11 @@ app.include_router(chat_router)
 app.include_router(dashboard_router)
 app.include_router(embedding_router)
 app.include_router(kb_router)
+app.include_router(kb_optimized_router)
 app.include_router(llm_router)
 app.include_router(rag_router)
 app.include_router(sessions_router)
+app.include_router(tenants_router)
 
 
 if __name__ == "__main__":
diff --git a/ai-service/app/models/__init__.py b/ai-service/app/models/__init__.py
index a97360e..cbbe9e7 100644
--- a/ai-service/app/models/__init__.py
+++ b/ai-service/app/models/__init__.py
@@ -49,6 +49,7 @@ class ChatResponse(BaseModel):
 class ErrorCode(str, Enum):
     INVALID_REQUEST = "INVALID_REQUEST"
     MISSING_TENANT_ID = "MISSING_TENANT_ID"
+    INVALID_TENANT_ID = "INVALID_TENANT_ID"
     INTERNAL_ERROR = "INTERNAL_ERROR"
     SERVICE_UNAVAILABLE = "SERVICE_UNAVAILABLE"
     TIMEOUT = "TIMEOUT"
diff --git a/ai-service/app/models/entities.py b/ai-service/app/models/entities.py
index 6532097..cf41595 100644
--- a/ai-service/app/models/entities.py
+++ b/ai-service/app/models/entities.py
@@ -102,6 +102,22 @@ class SessionStatus(str, Enum):
     EXPIRED = "expired"
 
 
+class Tenant(SQLModel, table=True):
+    """
+    [AC-AISVC-10] Tenant entity for storing tenant information.
+    Tenant ID format: name@ash@year (e.g., szmp@ash@2026)
+    """
+
+    __tablename__ = "tenants"
+
+    id: uuid.UUID = Field(default_factory=uuid.uuid4, primary_key=True)
+    tenant_id: str = Field(..., description="Full tenant ID (format: name@ash@year)", unique=True, index=True)
+    name: str = Field(..., description="Tenant display name (first part of tenant_id)")
+    year: str = Field(..., description="Year part from tenant_id")
+    created_at: datetime = Field(default_factory=datetime.utcnow, description="Creation time")
+    updated_at: datetime = Field(default_factory=datetime.utcnow, description="Last update time")
+
+
 class KnowledgeBase(SQLModel, table=True):
     """
     [AC-ASA-01] Knowledge base entity with tenant isolation.