diff --git a/plugins/src/test/java/org/tron/plugins/DbCopyTest.java b/plugins/src/test/java/org/tron/plugins/DbCopyTest.java
index c5cc8f2bb31..9e488a592aa 100644
--- a/plugins/src/test/java/org/tron/plugins/DbCopyTest.java
+++ b/plugins/src/test/java/org/tron/plugins/DbCopyTest.java
@@ -11,7 +11,7 @@ public class DbCopyTest extends DbTest {
   @Test
   public void testRun() {
     String[] args = new String[] { "db", "cp",  INPUT_DIRECTORY,
-        tmpDir + UUID.randomUUID()};
+        genarateTmpDir()};
     Assert.assertEquals(0, cli.execute(args));
   }
 
@@ -32,7 +32,7 @@ public void testNotExist() {
   @Test
   public void testEmpty() throws IOException {
     String[] args = new String[] {"db", "cp", temporaryFolder.newFolder().toString(),
-        tmpDir + UUID.randomUUID()};
+        genarateTmpDir()};
     Assert.assertEquals(0, cli.execute(args));
   }
 
@@ -46,7 +46,7 @@ public void testDestIsExist() throws IOException {
   @Test
   public void testSrcIsFile() throws IOException {
     String[] args = new String[] {"db", "cp", temporaryFolder.newFile().toString(),
-        tmpDir + UUID.randomUUID()};
+        genarateTmpDir()};
     Assert.assertEquals(403, cli.execute(args));
   }
 
diff --git a/plugins/src/test/java/org/tron/plugins/DbTest.java b/plugins/src/test/java/org/tron/plugins/DbTest.java
index 8a5f9de4a67..8605fa18d50 100644
--- a/plugins/src/test/java/org/tron/plugins/DbTest.java
+++ b/plugins/src/test/java/org/tron/plugins/DbTest.java
@@ -86,4 +86,14 @@ private static void initDB(File file) throws IOException {
       }
     }
   }
+
+  /**
+   * Generate a not-exist temporary directory path.
+   * @return temporary path
+   */
+  public String genarateTmpDir() {
+    File dir = Paths.get(tmpDir, UUID.randomUUID().toString()).toFile();
+    dir.deleteOnExit();
+    return dir.getPath();
+  }
 }