diff --git a/src/main/java/com/superbiz/agent/domain/entity/ApiDocument.java b/src/main/java/com/superbiz/agent/domain/entity/ApiDocument.java
index 7000cc8..6705a2f 100644
--- a/src/main/java/com/superbiz/agent/domain/entity/ApiDocument.java
+++ b/src/main/java/com/superbiz/agent/domain/entity/ApiDocument.java
@@ -38,7 +38,7 @@ public class ApiDocument {
     // 文档分类
     @Enumerated(EnumType.STRING)
     @Column(name = "fault_category", length = 32, columnDefinition = "VARCHAR(32)")
-    private FaultCategory faultCategory = FaultCategory.EXTERNAL_API;
+    private FaultCategory faultCategory = FaultCategory.GENERAL;
 
     @Column(name = "fault_source", length = 128)
     private String faultSource;
diff --git a/src/main/java/com/superbiz/agent/domain/enums/FaultCategory.java b/src/main/java/com/superbiz/agent/domain/enums/FaultCategory.java
index 8bde91f..62f8217 100644
--- a/src/main/java/com/superbiz/agent/domain/enums/FaultCategory.java
+++ b/src/main/java/com/superbiz/agent/domain/enums/FaultCategory.java
@@ -1,17 +1,14 @@
 package com.superbiz.agent.domain.enums;
 
 /**
- * 故障类别枚举
+ * 文档分类枚举
  */
 public enum FaultCategory {
-    EXTERNAL_API("外部接口调用失败"),
-    INTERNAL_ERROR("系统内部错误"),
-    DATABASE("数据库问题"),
-    CACHE("缓存问题"),
-    NETWORK("网络问题"),
-    THREAD("线程问题"),
-    MEMORY("内存问题"),
-    CONFIG("配置问题");
+    API("API 接口文档"),
+    INFRASTRUCTURE("基础设施文档"),
+    DOMAIN("领域业务文档"),
+    TROUBLESHOOTING("故障排查文档"),
+    GENERAL("通用文档");
 
     private final String description;
 
@@ -22,4 +19,26 @@ public enum FaultCategory {
     public String getDescription() {
         return description;
     }
+
+    /**
+     * 从字符串映射到枚举
+     */
+    public static FaultCategory fromString(String category) {
+        if (category == null || category.isEmpty()) {
+            return GENERAL;
+        }
+
+        switch (category.toLowerCase()) {
+            case "api":
+                return API;
+            case "infrastructure":
+                return INFRASTRUCTURE;
+            case "domain":
+                return DOMAIN;
+            case "troubleshooting":
+                return TROUBLESHOOTING;
+            default:
+                return GENERAL;
+        }
+    }
 }
diff --git a/src/main/java/com/superbiz/agent/service/DocumentManagementService.java b/src/main/java/com/superbiz/agent/service/DocumentManagementService.java
index 400e92d..895cd4c 100644
--- a/src/main/java/com/superbiz/agent/service/DocumentManagementService.java
+++ b/src/main/java/com/superbiz/agent/service/DocumentManagementService.java
@@ -287,12 +287,12 @@ public class DocumentManagementService {
      */
     private FaultCategory parseFaultCategory(String category) {
         if (category == null || category.isBlank()) {
-            return FaultCategory.EXTERNAL_API;
+            return FaultCategory.GENERAL;
         }
         try {
             return FaultCategory.valueOf(category.toUpperCase());
         } catch (IllegalArgumentException e) {
-            return FaultCategory.EXTERNAL_API;
+            return FaultCategory.GENERAL;
         }
     }
 
diff --git a/src/main/java/com/superbiz/agent/service/KnowledgeBaseInitService.java b/src/main/java/com/superbiz/agent/service/KnowledgeBaseInitService.java
index 5d57cdf..bc76c11 100644
--- a/src/main/java/com/superbiz/agent/service/KnowledgeBaseInitService.java
+++ b/src/main/java/com/superbiz/agent/service/KnowledgeBaseInitService.java
@@ -1,6 +1,7 @@
 package com.superbiz.agent.service;
 
 import com.superbiz.agent.domain.entity.ApiDocument;
+import com.superbiz.agent.domain.enums.FaultCategory;
 import com.superbiz.agent.repository.ApiDocumentRepository;
 import com.superbiz.agent.dto.KnowledgeEntry;
 import com.superbiz.agent.dto.Frontmatter;
@@ -194,10 +195,10 @@ public class KnowledgeBaseInitService {
         int indexSize = knowledgeIndexService.getIndexSize();
         logger.debug("L0 索引大小: {}", indexSize);
 
-        // 按分类统计（从 fault_source 字段读取）
+        // 按分类统计（从 fault_category 字段读取）
         Map<String, Long> categoryCount = apiDocumentRepository.findAll().stream()
                 .collect(Collectors.groupingBy(
-                        doc -> doc.getFaultSource() != null ? doc.getFaultSource() : "general",
+                        doc -> doc.getFaultCategory() != null ? doc.getFaultCategory().name() : "GENERAL",
                         Collectors.counting()
                 ));
         stats.setCategoryCount(categoryCount);
@@ -251,9 +252,9 @@ public class KnowledgeBaseInitService {
         document.setApiName(title);  // 使用 title 作为 apiName
         document.setStatus("PENDING");  // 初始状态为 PENDING，索引成功后更新为 INDEXED
 
-        // 直接使用 fault_source 字段存储 category（api, infrastructure, domain 等）
-        // fault_category 字段名虽然不太贴切，但可以用来存储文档分类
-        document.setFaultSource(category);
+        // 映射 category 到 FaultCategory 枚举
+        FaultCategory faultCategory = FaultCategory.fromString(category);
+        document.setFaultCategory(faultCategory);
 
         // 将 frontmatter 信息保存到 metadata（JSON 格式）
         String metadataJson = String.format(
diff --git a/src/main/java/com/superbiz/agent/service/KnowledgeIndexService.java b/src/main/java/com/superbiz/agent/service/KnowledgeIndexService.java
index 1950bfa..85367cb 100644
--- a/src/main/java/com/superbiz/agent/service/KnowledgeIndexService.java
+++ b/src/main/java/com/superbiz/agent/service/KnowledgeIndexService.java
@@ -1,5 +1,7 @@
 package com.superbiz.agent.service;
 
+import com.superbiz.agent.domain.entity.ApiDocument;
+import com.superbiz.agent.repository.ApiDocumentRepository;
 import com.superbiz.agent.dto.Frontmatter;
 import com.superbiz.agent.dto.KnowledgeEntry;
 import lombok.extern.slf4j.Slf4j;
@@ -12,6 +14,8 @@ import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.stream.Collectors;