diff --git a/algorithm-service/algorithm-ai-service/src/main/java/com/stephen/cloud/ai/controller/KnowledgeBaseController.java b/algorithm-service/algorithm-ai-service/src/main/java/com/stephen/cloud/ai/controller/KnowledgeBaseController.java
index c11c3a0..9ec4cc1 100644
--- a/algorithm-service/algorithm-ai-service/src/main/java/com/stephen/cloud/ai/controller/KnowledgeBaseController.java
+++ b/algorithm-service/algorithm-ai-service/src/main/java/com/stephen/cloud/ai/controller/KnowledgeBaseController.java
@@ -19,6 +19,7 @@
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.annotation.Resource;
 import jakarta.servlet.http.HttpServletRequest;
+import org.springframework.dao.DataIntegrityViolationException;
 import org.springframework.web.bind.annotation.*;
 
 /**
@@ -48,7 +49,12 @@ public BaseResponse<Long> addKnowledgeBase(@RequestBody KnowledgeBaseAddRequest
         ThrowUtils.throwIf(!knowledgeBaseService.isNameUnique(knowledgeBase.getName(), null), ErrorCode.OPERATION_ERROR, "知识库名称已存在");
         knowledgeBase.setUserId(SecurityUtils.getLoginUserId());
         knowledgeBase.setDocumentCount(0);
-        boolean result = knowledgeBaseService.save(knowledgeBase);
+        boolean result;
+        try {
+            result = knowledgeBaseService.save(knowledgeBase);
+        } catch (DataIntegrityViolationException e) {
+            throw new BusinessException(ErrorCode.OPERATION_ERROR, "知识库名称已存在");
+        }
         ThrowUtils.throwIf(!result, ErrorCode.OPERATION_ERROR);
         return ResultUtils.success(knowledgeBase.getId());
     }
diff --git a/algorithm-service/algorithm-ai-service/src/test/java/com/stephen/cloud/ai/controller/KnowledgeBaseControllerTest.java b/algorithm-service/algorithm-ai-service/src/test/java/com/stephen/cloud/ai/controller/KnowledgeBaseControllerTest.java
new file mode 100644
index 0000000..03dface
--- /dev/null
+++ b/algorithm-service/algorithm-ai-service/src/test/java/com/stephen/cloud/ai/controller/KnowledgeBaseControllerTest.java
@@ -0,0 +1,57 @@
+package com.stephen.cloud.ai.controller;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.stephen.cloud.ai.service.KnowledgeBaseService;
+import com.stephen.cloud.api.ai.model.dto.knowledgebase.KnowledgeBaseAddRequest;
+import com.stephen.cloud.common.auth.utils.SecurityUtils;
+import com.stephen.cloud.common.common.ErrorCode;
+import com.stephen.cloud.common.web.exception.GlobalExceptionHandler;
+import org.junit.jupiter.api.Test;
+import org.mockito.MockedStatic;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.http.MediaType;
+import org.springframework.test.util.ReflectionTestUtils;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+class KnowledgeBaseControllerTest {
+
+    private final ObjectMapper objectMapper = new ObjectMapper();
+
+    @Test
+    void addKnowledgeBaseShouldReturnFriendlyMessageWhenUniqueConstraintIsHit() throws Exception {
+        KnowledgeBaseService knowledgeBaseService = mock(KnowledgeBaseService.class);
+        when(knowledgeBaseService.isNameUnique("排序算法知识库", null)).thenReturn(true);
+        when(knowledgeBaseService.save(any()))
+                .thenThrow(new DataIntegrityViolationException("Duplicate entry"));
+
+        KnowledgeBaseController controller = new KnowledgeBaseController();
+        ReflectionTestUtils.setField(controller, "knowledgeBaseService", knowledgeBaseService);
+
+        MockMvc mockMvc = MockMvcBuilders.standaloneSetup(controller)
+                .setControllerAdvice(new GlobalExceptionHandler())
+                .build();
+
+        KnowledgeBaseAddRequest request = new KnowledgeBaseAddRequest();
+        request.setName("排序算法知识库");
+        request.setDescription("排序算法知识库");
+
+        try (MockedStatic<SecurityUtils> securityUtils = org.mockito.Mockito.mockStatic(SecurityUtils.class)) {
+            securityUtils.when(SecurityUtils::getLoginUserId).thenReturn(1L);
+
+            mockMvc.perform(post("/ai/kb/add")
+                            .contentType(MediaType.APPLICATION_JSON)
+                            .content(objectMapper.writeValueAsString(request)))
+                    .andExpect(status().isOk())
+                    .andExpect(jsonPath("$.code").value(ErrorCode.OPERATION_ERROR.getCode()))
+                    .andExpect(jsonPath("$.message").value("知识库名称已存在"));
+        }
+    }
+}
diff --git a/sql/README.md b/sql/README.md
index 6bc50ef..1cced16 100644
--- a/sql/README.md
+++ b/sql/README.md
@@ -29,6 +29,13 @@ done
 mysql -u root -p < ai_chat_record.sql
 ```
 
+### 3. 保持表结构为最新版本
+
+`algorithm.sql` 已包含最新的 `knowledge_base` 表结构，其中知识库唯一索引已更新为 `(name, is_delete)`，可支持逻辑删除后重建同名知识库。
+
+如果是新环境，直接执行最新版 `algorithm.sql` 即可。
+如果是已有环境，请将现网 `knowledge_base` 表的唯一索引同步到 `algorithm.sql` 中的最新定义后，再发布包含后端异常兜底的服务版本。
+
 ## 📝 表设计规范
 
 - **字符集**: 统一使用 `utf8mb4`，支持 Emoji 存储。
@@ -44,3 +51,4 @@ mysql -u root -p < ai_chat_record.sql
 1. **环境差异**: 生产环境建议通过 Nacos 或环境变量动态注入数据库连接信息。
 2. **性能优化**: 日志类表（如 `api_access_log`）建议定期归档或清理。
 3. **安全**: 避免修改 `root` 权限直接运行，建议为每个库创建独立账号。
+4. **知识库重名修复**: 若知识库采用逻辑删除，唯一索引需要包含 `is_delete`，否则“删除后重建同名知识库”会在数据库层失败。
diff --git a/sql/algorithm.sql b/sql/algorithm.sql
index e36059d..ba41eb9 100644
--- a/sql/algorithm.sql
+++ b/sql/algorithm.sql
@@ -159,7 +159,7 @@ CREATE TABLE `knowledge_base`
     `update_time`    datetime     NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间',
     `is_delete`      tinyint      NOT NULL DEFAULT 0 COMMENT '是否删除',
     PRIMARY KEY (`id`),
-    UNIQUE KEY `uk_name` (`name`) COMMENT '知识库名称唯一索引',
+    UNIQUE KEY `uk_name_is_delete` (`name`, `is_delete`) COMMENT '知识库名称+删除状态唯一索引',
     KEY `idx_user_id` (`user_id`) COMMENT '创建用户ID索引'
 ) ENGINE = InnoDB
   DEFAULT CHARSET = utf8mb4