diff --git a/config/src/test/java/com/alibaba/nacos/config/server/service/datasource/ExternalDataSourcePropertiesTest.java b/config/src/test/java/com/alibaba/nacos/config/server/service/datasource/ExternalDataSourcePropertiesTest.java
new file mode 100644
index 00000000000..d9adc79dd12
--- /dev/null
+++ b/config/src/test/java/com/alibaba/nacos/config/server/service/datasource/ExternalDataSourcePropertiesTest.java
@@ -0,0 +1,113 @@
+package com.alibaba.nacos.config.server.service.datasource;
+
+import java.util.List;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.springframework.mock.env.MockEnvironment;
+
+import com.zaxxer.hikari.HikariDataSource;
+
+public class ExternalDataSourcePropertiesTest {
+
+    public static final String JDBC_URL =
+        "jdbc:mysql://127.0.0.1:3306/nacos_devtest?characterEncoding=utf8&connectTimeout=1000&socketTimeout=3000&autoReconnect=true&useUnicode=true&useSSL=false&serverTimezone=UTC";
+    public static final String PASSWORD = "nacos";
+    public static final String USERNAME = "nacos_devtest";
+
+    @Test
+    public void external_datasource_normaly() {
+        HikariDataSource expectedDataSource = new HikariDataSource();
+        expectedDataSource.setJdbcUrl(JDBC_URL);
+        expectedDataSource.setUsername(USERNAME);
+        expectedDataSource.setPassword(PASSWORD);
+        MockEnvironment environment = new MockEnvironment();
+        environment.setProperty("db.num", "1");
+        environment.setProperty("db.user", USERNAME);
+        environment.setProperty("db.password", PASSWORD);
+        environment.setProperty("db.url.0", JDBC_URL);
+        List<HikariDataSource> dataSources = new ExternalDataSourceProperties().build(environment, (dataSource -> {
+            Assert.assertEquals(dataSource.getJdbcUrl(), expectedDataSource.getJdbcUrl());
+            Assert.assertEquals(dataSource.getUsername(), expectedDataSource.getUsername());
+            Assert.assertEquals(dataSource.getPassword(), expectedDataSource.getPassword());
+
+        }));
+        Assert.assertEquals(dataSources.size(), 1);
+    }
+
+    @Test
+    public void external_datasource_to_assert_multi_jdbc_url() {
+
+        HikariDataSource expectedDataSource = new HikariDataSource();
+        expectedDataSource.setJdbcUrl(JDBC_URL);
+        expectedDataSource.setUsername(USERNAME);
+        expectedDataSource.setPassword(PASSWORD);
+        MockEnvironment environment = new MockEnvironment();
+        environment.setProperty("db.num", "2");
+        environment.setProperty("db.user", USERNAME);
+        environment.setProperty("db.password", PASSWORD);
+        environment.setProperty("db.url.0", JDBC_URL);
+        environment.setProperty("db.url.1", JDBC_URL);
+        List<HikariDataSource> dataSources = new ExternalDataSourceProperties().build(environment, (dataSource -> {
+            Assert.assertEquals(dataSource.getJdbcUrl(), expectedDataSource.getJdbcUrl());
+            Assert.assertEquals(dataSource.getUsername(), expectedDataSource.getUsername());
+            Assert.assertEquals(dataSource.getPassword(), expectedDataSource.getPassword());
+
+        }));
+        Assert.assertEquals(dataSources.size(), 2);
+    }
+
+    @Test
+    public void external_datasource_to_assert_multi_password_and_username() {
+
+        HikariDataSource expectedDataSource = new HikariDataSource();
+        expectedDataSource.setJdbcUrl(JDBC_URL);
+        expectedDataSource.setUsername(USERNAME);
+        expectedDataSource.setPassword(PASSWORD);
+        MockEnvironment environment = new MockEnvironment();
+        environment.setProperty("db.num", "2");
+        environment.setProperty("db.user.0", USERNAME);
+        environment.setProperty("db.user.1", USERNAME);
+        environment.setProperty("db.password.0", PASSWORD);
+        environment.setProperty("db.password.1", PASSWORD);
+        environment.setProperty("db.url.0", JDBC_URL);
+        environment.setProperty("db.url.1", JDBC_URL);
+        List<HikariDataSource> dataSources = new ExternalDataSourceProperties().build(environment, (dataSource -> {
+            Assert.assertEquals(dataSource.getJdbcUrl(), expectedDataSource.getJdbcUrl());
+            Assert.assertEquals(dataSource.getUsername(), expectedDataSource.getUsername());
+            Assert.assertEquals(dataSource.getPassword(), expectedDataSource.getPassword());
+
+        }));
+        Assert.assertEquals(dataSources.size(), 2);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void external_datasource_to_assert_illegal_argument() {
+
+        MockEnvironment environment = new MockEnvironment();
+        new ExternalDataSourceProperties().build(environment, null);
+
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void external_datasource_to_assert_illegal_argument_2() {
+
+        HikariDataSource expectedDataSource = new HikariDataSource();
+        expectedDataSource.setJdbcUrl(JDBC_URL);
+        expectedDataSource.setUsername(USERNAME);
+        expectedDataSource.setPassword(PASSWORD);
+        MockEnvironment environment = new MockEnvironment();
+        // error num of db
+        environment.setProperty("db.num", "2");
+        environment.setProperty("db.user", USERNAME);
+        environment.setProperty("db.password", PASSWORD);
+        environment.setProperty("db.url.0", JDBC_URL);
+        List<HikariDataSource> dataSources = new ExternalDataSourceProperties().build(environment, (dataSource -> {
+            Assert.assertEquals(dataSource.getJdbcUrl(), expectedDataSource.getJdbcUrl());
+            Assert.assertEquals(dataSource.getUsername(), expectedDataSource.getUsername());
+            Assert.assertEquals(dataSource.getPassword(), expectedDataSource.getPassword());
+
+        }));
+    }
+
+}