diff --git a/backend/src/main/java/com/xly/erp/module/mod/service/ModuleService.java b/backend/src/main/java/com/xly/erp/module/mod/service/ModuleService.java
index 798d0ab..e17f15f 100644
--- a/backend/src/main/java/com/xly/erp/module/mod/service/ModuleService.java
+++ b/backend/src/main/java/com/xly/erp/module/mod/service/ModuleService.java
@@ -2,6 +2,9 @@ package com.xly.erp.module.mod.service;
 
 import com.xly.erp.module.mod.dto.CreateModuleDTO;
 import com.xly.erp.module.mod.dto.UpdateModuleDTO;
+import com.xly.erp.module.mod.vo.ModuleTreeVO;
+
+import java.util.List;
 
 public interface ModuleService {
     Integer create(CreateModuleDTO dto);
@@ -9,4 +12,6 @@ public interface ModuleService {
     Integer update(Integer id, UpdateModuleDTO dto);
 
     void delete(Integer id);
+
+    List<ModuleTreeVO> listTree(String keyword);
 }
diff --git a/backend/src/main/java/com/xly/erp/module/mod/service/impl/ModuleServiceImpl.java b/backend/src/main/java/com/xly/erp/module/mod/service/impl/ModuleServiceImpl.java
index 2187eff..b272bb2 100644
--- a/backend/src/main/java/com/xly/erp/module/mod/service/impl/ModuleServiceImpl.java
+++ b/backend/src/main/java/com/xly/erp/module/mod/service/impl/ModuleServiceImpl.java
@@ -7,6 +7,7 @@ import com.xly.erp.common.security.SecurityContextHelper;
 import com.xly.erp.module.mod.dto.CreateModuleDTO;
 import com.xly.erp.module.mod.dto.UpdateModuleDTO;
 import com.xly.erp.module.mod.entity.Module;
+import com.xly.erp.module.mod.vo.ModuleTreeVO;
 import com.xly.erp.module.mod.mapper.ModuleMapper;
 import com.xly.erp.module.mod.service.ModuleService;
 import org.springframework.dao.DuplicateKeyException;
@@ -14,6 +15,10 @@ import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 @Service
@@ -112,6 +117,42 @@ public class ModuleServiceImpl implements ModuleService {
         moduleMapper.updateById(entity);
     }
 
+    @Override
+    @Transactional(readOnly = true)
+    public List<ModuleTreeVO> listTree(String keyword) {
+        String normalized = keyword == null ? "" : keyword.trim();
+        if (normalized.length() > 100) {
+            throw new BizException(40001, "keyword 长度超过 100 字符");
+        }
+        List<Module> rows = moduleMapper.selectActiveByKeyword(normalized);
+        Map<Integer, ModuleTreeVO> idIndex = new HashMap<>();
+        for (Module m : rows) {
+            idIndex.put(m.getIIncrement(), toTreeVO(m));
+        }
+        List<ModuleTreeVO> roots = new ArrayList<>();
+        for (Module m : rows) {
+            ModuleTreeVO vo = idIndex.get(m.getIIncrement());
+            Integer parentId = m.getIParentId();
+            if (parentId != null && idIndex.containsKey(parentId)) {
+                idIndex.get(parentId).getChildren().add(vo);
+            } else {
+                roots.add(vo);
+            }
+        }
+        return roots;
+    }
+
+    private ModuleTreeVO toTreeVO(Module m) {
+        ModuleTreeVO vo = new ModuleTreeVO();
+        vo.setIIncrement(m.getIIncrement());
+        vo.setSModuleNameZh(m.getSModuleNameZh());
+        vo.setSDisplayType(m.getSDisplayType());
+        vo.setSManageDeptEn(m.getSManageDeptEn());
+        vo.setIParentId(m.getIParentId());
+        vo.setISortOrder(m.getISortOrder());
+        return vo;
+    }
+
     private void validateParent(Integer id, Integer parentId) {
         if (parentId == null) {
             return;
diff --git a/backend/src/main/java/com/xly/erp/module/mod/vo/ModuleTreeVO.java b/backend/src/main/java/com/xly/erp/module/mod/vo/ModuleTreeVO.java
new file mode 100644
index 0000000..461a131
--- /dev/null
+++ b/backend/src/main/java/com/xly/erp/module/mod/vo/ModuleTreeVO.java
@@ -0,0 +1,45 @@
+package com.xly.erp.module.mod.vo;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ModuleTreeVO {
+
+    @JsonProperty("iIncrement")
+    private Integer iIncrement;
+
+    @JsonProperty("sModuleNameZh")
+    private String sModuleNameZh;
+
+    @JsonProperty("sDisplayType")
+    private String sDisplayType;
+
+    @JsonProperty("sManageDeptEn")
+    private String sManageDeptEn;
+
+    @JsonProperty("iParentId")
+    private Integer iParentId;
+
+    @JsonProperty("iSortOrder")
+    private Integer iSortOrder;
+
+    @JsonProperty("children")
+    private List<ModuleTreeVO> children = new ArrayList<>();
+
+    public Integer getIIncrement() { return iIncrement; }
+    public void setIIncrement(Integer iIncrement) { this.iIncrement = iIncrement; }
+    public String getSModuleNameZh() { return sModuleNameZh; }
+    public void setSModuleNameZh(String sModuleNameZh) { this.sModuleNameZh = sModuleNameZh; }
+    public String getSDisplayType() { return sDisplayType; }
+    public void setSDisplayType(String sDisplayType) { this.sDisplayType = sDisplayType; }
+    public String getSManageDeptEn() { return sManageDeptEn; }
+    public void setSManageDeptEn(String sManageDeptEn) { this.sManageDeptEn = sManageDeptEn; }
+    public Integer getIParentId() { return iParentId; }
+    public void setIParentId(Integer iParentId) { this.iParentId = iParentId; }
+    public Integer getISortOrder() { return iSortOrder; }
+    public void setISortOrder(Integer iSortOrder) { this.iSortOrder = iSortOrder; }
+    public List<ModuleTreeVO> getChildren() { return children; }
+    public void setChildren(List<ModuleTreeVO> children) { this.children = children; }
+}
diff --git a/backend/src/test/java/com/xly/erp/module/mod/service/ModuleServiceImplTest.java b/backend/src/test/java/com/xly/erp/module/mod/service/ModuleServiceImplTest.java
index ca40fb1..4e49e77 100644
--- a/backend/src/test/java/com/xly/erp/module/mod/service/ModuleServiceImplTest.java
+++ b/backend/src/test/java/com/xly/erp/module/mod/service/ModuleServiceImplTest.java
@@ -8,6 +8,7 @@ import com.xly.erp.module.mod.dto.UpdateModuleDTO;
 import com.xly.erp.module.mod.entity.Module;
 import com.xly.erp.module.mod.mapper.ModuleMapper;
 import com.xly.erp.module.mod.service.impl.ModuleServiceImpl;
+import com.xly.erp.module.mod.vo.ModuleTreeVO;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -17,6 +18,7 @@ import org.springframework.security.authentication.UsernamePasswordAuthenticatio
 import org.springframework.security.core.context.SecurityContextHolder;
 
 import java.util.Collections;
+import java.util.List;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
@@ -306,6 +308,85 @@ class ModuleServiceImplTest {
         assertThat(captor.getValue().getSDeletedBy()).isEqualTo("BOB");
     }
 
+    @Test
+    void listTree_emptyKeyword_invokesMapperWithEmptyString_returnsAssembledTree() {
+        Module root1 = treeRow(1, "根1", null, 0);
+        Module root2 = treeRow(2, "根2", null, 0);
+        Module child1 = treeRow(3, "子1", 1, 0);
+        Module child2 = treeRow(4, "子2", 1, 1);
+        Module grand1 = treeRow(5, "孙1", 3, 0);
+        when(moduleMapper.selectActiveByKeyword("")).thenReturn(List.of(root1, root2, child1, child2, grand1));
+
+        List<ModuleTreeVO> result = service.listTree("");
+
+        assertThat(result).extracting(ModuleTreeVO::getIIncrement).containsExactly(1, 2);
+        assertThat(result.get(0).getChildren()).extracting(ModuleTreeVO::getIIncrement).containsExactly(3, 4);
+        assertThat(result.get(0).getChildren().get(0).getChildren()).extracting(ModuleTreeVO::getIIncrement).containsExactly(5);
+        assertThat(result.get(1).getChildren()).isEmpty();
+    }
+
+    @Test
+    void listTree_nullKeyword_treatedAsEmpty() {
+        when(moduleMapper.selectActiveByKeyword("")).thenReturn(List.of());
+        service.listTree(null);
+        ArgumentCaptor<String> captor = ArgumentCaptor.forClass(String.class);
+        verify(moduleMapper).selectActiveByKeyword(captor.capture());
+        assertThat(captor.getValue()).isEqualTo("");
+    }
+
+    @Test
+    void listTree_blankKeyword_treatedAsEmpty() {
+        when(moduleMapper.selectActiveByKeyword("")).thenReturn(List.of());
+        service.listTree("   ");
+        verify(moduleMapper).selectActiveByKeyword("");
+    }
+
+    @Test
+    void listTree_keywordTooLong_throws40001() {
+        String longKw = "x".repeat(101);
+        assertThatThrownBy(() -> service.listTree(longKw))
+                .isInstanceOf(BizException.class)
+                .hasFieldOrPropertyWithValue("code", 40001);
+        verify(moduleMapper, never()).selectActiveByKeyword(any());
+    }
+
+    @Test
+    void listTree_returnsEmptyListWhenNoMatch() {
+        when(moduleMapper.selectActiveByKeyword("xyz")).thenReturn(List.of());
+        List<ModuleTreeVO> result = service.listTree("xyz");
+        assertThat(result).isEmpty();
+    }
+
+    @Test
+    void listTree_orphansBecomeRootsInForest() {
+        Module orphan = treeRow(3, "孤儿", 99, 0);
+        when(moduleMapper.selectActiveByKeyword("")).thenReturn(List.of(orphan));
+
+        List<ModuleTreeVO> result = service.listTree("");
+
+        assertThat(result).hasSize(1);
+        assertThat(result.get(0).getIIncrement()).isEqualTo(3);
+        assertThat(result.get(0).getChildren()).isEmpty();
+    }
+
+    @Test
+    void listTree_keywordIsTrimmedBeforeQuery() {
+        when(moduleMapper.selectActiveByKeyword("系统")).thenReturn(List.of());
+        service.listTree("  系统  ");
+        verify(moduleMapper).selectActiveByKeyword("系统");
+    }
+
+    private Module treeRow(int id, String name, Integer parentId, int sortOrder) {
+        Module m = new Module();
+        m.setIIncrement(id);
+        m.setSModuleNameZh(name);
+        m.setSDisplayType("手机端");
+        m.setSManageDeptEn("IT");
+        m.setIParentId(parentId);
+        m.setISortOrder(sortOrder);
+        return m;
+    }
+
     private UpdateModuleDTO baseUpdateDto() {
         UpdateModuleDTO dto = new UpdateModuleDTO();
         dto.setSDisplayType("手机端");