diff --git a/fe/fe-core/src/test/java/org/apache/doris/cluster/DecommissionBackendTest.java b/fe/fe-core/src/test/java/org/apache/doris/cluster/DecommissionBackendTest.java
index 209f8a112762308..e689723cdf8db21 100644
--- a/fe/fe-core/src/test/java/org/apache/doris/cluster/DecommissionBackendTest.java
+++ b/fe/fe-core/src/test/java/org/apache/doris/cluster/DecommissionBackendTest.java
@@ -18,11 +18,15 @@
 package org.apache.doris.cluster;
 
 import org.apache.doris.analysis.AlterSystemStmt;
+import org.apache.doris.catalog.Database;
 import org.apache.doris.catalog.Env;
+import org.apache.doris.catalog.MaterializedIndex;
+import org.apache.doris.catalog.OlapTable;
 import org.apache.doris.common.AnalysisException;
 import org.apache.doris.common.Config;
 import org.apache.doris.common.FeConstants;
 import org.apache.doris.system.Backend;
+import org.apache.doris.system.SystemInfoService;
 import org.apache.doris.utframe.TestWithFeService;
 
 import com.google.common.collect.ImmutableMap;
@@ -55,6 +59,7 @@ protected void beforeCreatingConnectContext() throws Exception {
         FeConstants.tablet_checker_interval_ms = 1000;
         Config.tablet_repair_delay_factor_second = 1;
         Config.allow_replica_on_same_host = true;
+        Config.disable_balance = true;
     }
 
     @Test
@@ -103,11 +108,8 @@ public void testDecommissionBackend() throws Exception {
                 Env.getCurrentInvertedIndex().getTabletMetaMap().size());
 
         // 6. add backend
-        String addBackendStmtStr = "alter system add backend \"127.0.0.1:" + srcBackend.getHeartbeatPort() + "\"";
-        AlterSystemStmt addBackendStmt = (AlterSystemStmt) parseAndAnalyzeStmt(addBackendStmtStr);
-        Env.getCurrentEnv().getAlterInstance().processAlterCluster(addBackendStmt);
+        addNewBackend();
         Assertions.assertEquals(backendNum(), Env.getCurrentSystemInfo().getIdToBackend().size());
-
     }
 
     @Test
@@ -115,29 +117,38 @@ public void testDecommissionBackendWithDropTable() throws Exception {
         // 1. create connect context
         connectContext = createDefaultCtx();
 
-        ImmutableMap<Long, Backend> idToBackendRef = Env.getCurrentSystemInfo().getIdToBackend();
+        SystemInfoService infoService = Env.getCurrentSystemInfo();
+
+        ImmutableMap<Long, Backend> idToBackendRef = infoService.getIdToBackend();
         Assertions.assertEquals(backendNum(), idToBackendRef.size());
 
         // 2. create database db2
         createDatabase("db2");
         System.out.println(Env.getCurrentInternalCatalog().getDbNames());
 
+        long availableBeNum = infoService.getAllBackendIds(true).stream()
+                .filter(beId -> infoService.checkBackendScheduleAvailable(beId)).count();
+
         // 3. create table tbl1 tbl2
-        createTable("create table db2.tbl1(k1 int) distributed by hash(k1) buckets 3 properties('replication_num' = '2');");
+        createTable("create table db2.tbl1(k1 int) distributed by hash(k1) buckets 3 properties('replication_num' = '"
+                + availableBeNum + "');");
         createTable("create table db2.tbl2(k1 int) distributed by hash(k1) buckets 3 properties('replication_num' = '1');");
 
         // 4. query tablet num
         int tabletNum = Env.getCurrentInvertedIndex().getTabletMetaMap().size();
         Assertions.assertTrue(tabletNum > 0);
 
-        Backend srcBackend = null;
-        for (Backend backend : idToBackendRef.values()) {
-            if (Env.getCurrentInvertedIndex().getTabletIdsByBackendId(backend.getId()).size() > 0) {
-                srcBackend = backend;
-                break;
-            }
-        }
-        Assertions.assertTrue(srcBackend != null);
+        Database db = Env.getCurrentInternalCatalog().getDbOrMetaException("default_cluster:db2");
+        OlapTable tbl = (OlapTable) db.getTableOrMetaException("tbl1");
+        Assertions.assertNotNull(tbl);
+        long backendId = tbl.getPartitions().iterator().next()
+                .getMaterializedIndices(MaterializedIndex.IndexExtState.ALL).iterator().next()
+                .getTablets().iterator().next()
+                .getReplicas().iterator().next()
+                .getBackendId();
+
+        Backend srcBackend = infoService.getBackend(backendId);
+        Assertions.assertNotNull(srcBackend);
 
         // 5. drop table tbl1
         dropTable("db2.tbl1", false);
@@ -170,9 +181,7 @@ public void testDecommissionBackendWithDropTable() throws Exception {
         Assertions.assertDoesNotThrow(() -> recoverTable("db2.tbl1"));
         Assertions.assertDoesNotThrow(() -> showCreateTable(sql));
 
-        String addBackendStmtStr = "alter system add backend \"127.0.0.1:" + srcBackend.getHeartbeatPort() + "\"";
-        AlterSystemStmt addBackendStmt = (AlterSystemStmt) parseAndAnalyzeStmt(addBackendStmtStr);
-        Env.getCurrentEnv().getAlterInstance().processAlterCluster(addBackendStmt);
+        addNewBackend();
         Assertions.assertEquals(backendNum(), Env.getCurrentSystemInfo().getIdToBackend().size());
     }
 
diff --git a/fe/fe-core/src/test/java/org/apache/doris/utframe/TestWithFeService.java b/fe/fe-core/src/test/java/org/apache/doris/utframe/TestWithFeService.java
index 9a86b264a62a09d..b032ddd2a501777 100644
--- a/fe/fe-core/src/test/java/org/apache/doris/utframe/TestWithFeService.java
+++ b/fe/fe-core/src/test/java/org/apache/doris/utframe/TestWithFeService.java
@@ -125,6 +125,7 @@ public abstract class TestWithFeService {
     protected String runningDir = "fe/mocked/" + getClass().getSimpleName() + "/" + UUID.randomUUID() + "/";
     protected ConnectContext connectContext;
     protected boolean needCleanDir = true;
+    protected int lastFeRpcPort = 0;
 
     protected static final String DEFAULT_CLUSTER_PREFIX = "default_cluster:";
 
@@ -378,6 +379,7 @@ protected int startFEServerWithoutRetry(String runningDir)
         MockedFrontend frontend = new MockedFrontend();
         frontend.init(dorisHome + "/" + runningDir, feConfMap);
         frontend.start(new String[0]);
+        lastFeRpcPort = feRpcPort;
         return feRpcPort;
     }
 
@@ -434,6 +436,10 @@ protected void createDorisClusterWithMultiTag(String runningDir, int backendNum)
         checkBEHeartbeat(bes);
     }
 
+    protected Backend addNewBackend() throws IOException, InterruptedException {
+        return createBackend("127.0.0.1", lastFeRpcPort);
+    }
+
     protected Backend createBackend(String beHost, int feRpcPort) throws IOException, InterruptedException {
         IOException exception = null;
         for (int i = 0; i <= 3; i++) {