diff --git a/hutool-core/src/test/java/org/dromara/hutool/core/tree/IssueIAUSHRTest.java b/hutool-core/src/test/java/org/dromara/hutool/core/tree/IssueIAUSHRTest.java
index 574d8c318..67bbce7b9 100644
--- a/hutool-core/src/test/java/org/dromara/hutool/core/tree/IssueIAUSHRTest.java
+++ b/hutool-core/src/test/java/org/dromara/hutool/core/tree/IssueIAUSHRTest.java
@@ -2,6 +2,7 @@ package org.dromara.hutool.core.tree;
 
 import lombok.Data;
 import org.dromara.hutool.core.tree.parser.NodeParser;
+import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayList;
@@ -10,9 +11,49 @@ import java.util.List;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class IssueIAUSHRTest {
+
+	private final NodeParser<TestDept, Long> nodeParser = (dept, tree) ->
+		tree.setId(dept.getDeptId())
+			.setParentId(dept.getParentId())
+			.setName(dept.getDeptName());
+
+	private final TreeNodeConfig treeNodeConfig = new TreeNodeConfig()
+		.setIdKey("deptId")
+		.setNameKey("deptName")
+		.setParentIdKey("parentId");
+
+	/**
+	 * 理论上，你所有节点的ID都不应该重复，那你要构建一个列表形式的树结构，指定的这个rootId应该是A节点的parentId，而非A的id
+	 */
+	@Test
+	void buildTest() {
+		final List<TestDept> list = mockData();
+
+		final List<MapTree<Long>> build = TreeUtil.build(list, null, treeNodeConfig, nodeParser);
+		Assertions.assertEquals(1, build.size());
+		assertEquals("A", build.get(0).getName());
+		assertEquals(2, build.get(0).getChildren().size());
+		assertEquals("B", build.get(0).getChildren().get(0).getName());
+		assertEquals("C", build.get(0).getChildren().get(1).getName());
+	}
+
+	/**
+	 * 构建单节点时，如果指定的节点存在，则这个节点作为根节点
+	 */
 	@Test
 	void buildSingleTest() {
-		final List<TestDept> list= new ArrayList<>();
+		final List<TestDept> list = mockData();
+
+		final MapTree<Long> longTree = TreeUtil.buildSingle(list, 1L, treeNodeConfig, nodeParser);
+
+		assertEquals("A", longTree.getName());
+		assertEquals(2, longTree.getChildren().size());
+		assertEquals("B", longTree.getChildren().get(0).getName());
+		assertEquals("C", longTree.getChildren().get(1).getName());
+	}
+
+	private List<TestDept> mockData() {
+		final List<TestDept> list = new ArrayList<>();
 		TestDept sysDept = new TestDept();
 		sysDept.setDeptId(1L);
 		sysDept.setDeptName("A");
@@ -31,26 +72,11 @@ public class IssueIAUSHRTest {
 		sysDept.setParentId(1L);
 		list.add(sysDept);
 
-		final TreeNodeConfig treeNodeConfig = new TreeNodeConfig();
-		treeNodeConfig.setIdKey("deptId");
-		treeNodeConfig.setNameKey("deptName");
-		treeNodeConfig.setParentIdKey("parentId");
-
-		final NodeParser<TestDept,Long> nodeParser= (dept, tree) ->
-			tree.setId(dept.getDeptId())
-				.setParentId(dept.getParentId())
-				.setName(dept.getDeptName());
-
-		final MapTree<Long> longTree = TreeUtil.buildSingle(list, 1L, treeNodeConfig, nodeParser);
-
-		assertEquals("A", longTree.getName());
-		assertEquals(2, longTree.getChildren().size());
-		assertEquals("B", longTree.getChildren().get(0).getName());
-		assertEquals("C", longTree.getChildren().get(1).getName());
+		return list;
 	}
 
 	@Data
-	public static class TestDept {
+	static class TestDept {
 		private Long deptId;
 		private String deptName;
 		private Long parentId;