diff --git a/backend/src/main/java/com/xly/erp/module/mod/entity/ModuleEntity.java b/backend/src/main/java/com/xly/erp/module/mod/entity/ModuleEntity.java
new file mode 100644
index 0000000..4bb6c61
--- /dev/null
+++ b/backend/src/main/java/com/xly/erp/module/mod/entity/ModuleEntity.java
@@ -0,0 +1,71 @@
+package com.xly.erp.module.mod.entity;
+
+import com.baomidou.mybatisplus.annotation.IdType;
+import com.baomidou.mybatisplus.annotation.TableField;
+import com.baomidou.mybatisplus.annotation.TableId;
+import com.baomidou.mybatisplus.annotation.TableName;
+import lombok.Data;
+
+import java.time.LocalDateTime;
+
+/**
+ * 业务模块定义。表 {@code tModule}（详见 docs/03-数据库设计文档.md § tModule）。
+ *
+ * <p>字段名沿用 docs/03 的匈牙利前缀命名（i/s/t/b），保持 schema 与 Java 字段一一对应，
+ * 避免双向映射歧义。@TableField 显式声明列名以兼容 MyBatis-Plus 默认的下划线转换关闭场景。</p>
+ */
+@Data
+@TableName("tModule")
+public class ModuleEntity {
+
+    @TableId(value = "iIncrement", type = IdType.AUTO)
+    private Integer iIncrement;
+
+    @TableField("sId")
+    private String sId;
+
+    @TableField("sBrandsId")
+    private String sBrandsId;
+
+    @TableField("sSubsidiaryId")
+    private String sSubsidiaryId;
+
+    @TableField("tCreateDate")
+    private LocalDateTime tCreateDate;
+
+    @TableField("sDisplayType")
+    private String sDisplayType;
+
+    @TableField("sProcedureName")
+    private String sProcedureName;
+
+    @TableField("sModuleType")
+    private String sModuleType;
+
+    @TableField("sManageDeptEn")
+    private String sManageDeptEn;
+
+    @TableField("bShowPermission")
+    private Boolean bShowPermission;
+
+    @TableField("sModuleNameZh")
+    private String sModuleNameZh;
+
+    @TableField("iParentId")
+    private Integer iParentId;
+
+    @TableField("iSortOrder")
+    private Integer iSortOrder;
+
+    @TableField("sCreatedBy")
+    private String sCreatedBy;
+
+    @TableField("bDeleted")
+    private Boolean bDeleted;
+
+    @TableField("tDeletedDate")
+    private LocalDateTime tDeletedDate;
+
+    @TableField("sDeletedBy")
+    private String sDeletedBy;
+}
diff --git a/backend/src/main/java/com/xly/erp/module/mod/mapper/ModuleMapper.java b/backend/src/main/java/com/xly/erp/module/mod/mapper/ModuleMapper.java
new file mode 100644
index 0000000..7abc096
--- /dev/null
+++ b/backend/src/main/java/com/xly/erp/module/mod/mapper/ModuleMapper.java
@@ -0,0 +1,7 @@
+package com.xly.erp.module.mod.mapper;
+
+import com.baomidou.mybatisplus.core.mapper.BaseMapper;
+import com.xly.erp.module.mod.entity.ModuleEntity;
+
+public interface ModuleMapper extends BaseMapper<ModuleEntity> {
+}
diff --git a/backend/src/main/resources/mapper/mod/ModuleMapper.xml b/backend/src/main/resources/mapper/mod/ModuleMapper.xml
new file mode 100644
index 0000000..9e7b093
--- /dev/null
+++ b/backend/src/main/resources/mapper/mod/ModuleMapper.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+<mapper namespace="com.xly.erp.module.mod.mapper.ModuleMapper">
+    <!-- REQ-MOD-001 仅使用 BaseMapper 默认 SQL；后续 REQ 按需扩展自定义查询 -->
+</mapper>
diff --git a/backend/src/test/java/com/xly/erp/module/mod/mapper/ModuleMapperIT.java b/backend/src/test/java/com/xly/erp/module/mod/mapper/ModuleMapperIT.java
new file mode 100644
index 0000000..bd61361
--- /dev/null
+++ b/backend/src/test/java/com/xly/erp/module/mod/mapper/ModuleMapperIT.java
@@ -0,0 +1,77 @@
+package com.xly.erp.module.mod.mapper;
+
+import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
+import com.xly.erp.module.mod.entity.ModuleEntity;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.annotation.Rollback;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.LocalDateTime;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@SpringBootTest
+@ActiveProfiles("test")
+@Transactional
+@Rollback
+class ModuleMapperIT {
+
+    @Autowired ModuleMapper moduleMapper;
+
+    @Test
+    void insertAndSelectById_persistsAllFields() {
+        ModuleEntity e = new ModuleEntity();
+        e.setSDisplayType("前端业务");
+        e.setSProcedureName("sp_audit_test_" + System.nanoTime());
+        e.setSModuleType("USR");
+        e.setSManageDeptEn("IT");
+        e.setBShowPermission(false);
+        e.setSModuleNameZh("测试模块");
+        e.setIParentId(null);
+        e.setISortOrder(0);
+        e.setBDeleted(false);
+        e.setTCreateDate(LocalDateTime.now());
+
+        int rows = moduleMapper.insert(e);
+        assertThat(rows).isEqualTo(1);
+        assertThat(e.getIIncrement()).isNotNull().isPositive();
+
+        ModuleEntity loaded = moduleMapper.selectById(e.getIIncrement());
+        assertThat(loaded).isNotNull();
+        assertThat(loaded.getSDisplayType()).isEqualTo("前端业务");
+        assertThat(loaded.getSProcedureName()).isEqualTo(e.getSProcedureName());
+        assertThat(loaded.getSModuleType()).isEqualTo("USR");
+        assertThat(loaded.getSManageDeptEn()).isEqualTo("IT");
+        assertThat(loaded.getBShowPermission()).isFalse();
+        assertThat(loaded.getSModuleNameZh()).isEqualTo("测试模块");
+        assertThat(loaded.getIParentId()).isNull();
+        assertThat(loaded.getISortOrder()).isZero();
+        assertThat(loaded.getBDeleted()).isFalse();
+    }
+
+    @Test
+    void selectCountByProcedureName_returnsExisting() {
+        String name = "sp_audit_uniq_" + System.nanoTime();
+        ModuleEntity e = new ModuleEntity();
+        e.setSDisplayType("接口");
+        e.setSProcedureName(name);
+        e.setSModuleType("MOD");
+        e.setSManageDeptEn("IT");
+        e.setBShowPermission(false);
+        e.setSModuleNameZh("唯一性检测");
+        e.setISortOrder(0);
+        e.setBDeleted(false);
+        e.setTCreateDate(LocalDateTime.now());
+        moduleMapper.insert(e);
+
+        Long count = moduleMapper.selectCount(
+                new LambdaQueryWrapper<ModuleEntity>()
+                        .eq(ModuleEntity::getSProcedureName, name)
+                        .eq(ModuleEntity::getBDeleted, false)
+        );
+        assertThat(count).isEqualTo(1L);
+    }
+}