diff --git a/fe/fe-core/src/main/java/org/apache/doris/planner/DistributedPlanner.java b/fe/fe-core/src/main/java/org/apache/doris/planner/DistributedPlanner.java
index eb099c26ec..90dda46638 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/planner/DistributedPlanner.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/planner/DistributedPlanner.java
@@ -927,7 +927,7 @@ public class DistributedPlanner {
         if (isDistinct) {
             return createPhase2DistinctAggregationFragment(node, childFragment, fragments);
         } else {
-            if (canColocateAgg(node.getAggInfo(), childFragment.getInputDataPartition())) {
+            if (canColocateAgg(node.getAggInfo(), childFragment.getDataPartition())) {
                 childFragment.addPlanRoot(node);
                 childFragment.setHasColocatePlanNode(true);
                 return childFragment;
@@ -942,7 +942,7 @@ public class DistributedPlanner {
      * 1. Session variables disable_colocate_plan = false
      * 2. The input data partition of child fragment < agg node partition exprs
      */
-    private boolean canColocateAgg(AggregateInfo aggregateInfo, List<DataPartition> childFragmentDataPartition) {
+    private boolean canColocateAgg(AggregateInfo aggregateInfo, DataPartition childFragmentDataPartition) {
         // Condition1
         if (ConnectContext.get().getSessionVariable().isDisableColocatePlan()) {
             LOG.debug("Agg node is not colocate in:" + ConnectContext.get().queryId()
@@ -952,10 +952,8 @@ public class DistributedPlanner {
 
         // Condition2
         List<Expr> aggPartitionExprs = aggregateInfo.getInputPartitionExprs();
-        for (DataPartition childDataPartition : childFragmentDataPartition) {
-            if (dataPartitionMatchAggInfo(childDataPartition, aggPartitionExprs)) {
-                return true;
-            }
+        if (dataPartitionMatchAggInfo(childFragmentDataPartition, aggPartitionExprs)) {
+            return true;
         }
         return false;
     }
diff --git a/fe/fe-core/src/main/java/org/apache/doris/planner/PlanFragment.java b/fe/fe-core/src/main/java/org/apache/doris/planner/PlanFragment.java
index 6f14e44067..c5d01e6249 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/planner/PlanFragment.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/planner/PlanFragment.java
@@ -329,15 +329,6 @@ public class PlanFragment extends TreeNode<PlanFragment> {
         dest.addChild(this);
     }
 
-    public List<DataPartition> getInputDataPartition() {
-        List<DataPartition> result = Lists.newArrayList();
-        result.add(getDataPartition());
-        for (PlanFragment child : children) {
-            result.add(child.getOutputPartition());
-        }
-        return result;
-    }
-
     public DataPartition getDataPartition() {
         return dataPartition;
     }
diff --git a/fe/fe-core/src/test/java/org/apache/doris/planner/ColocatePlanTest.java b/fe/fe-core/src/test/java/org/apache/doris/planner/ColocatePlanTest.java
index 43d062a806..716e3c68be 100644
--- a/fe/fe-core/src/test/java/org/apache/doris/planner/ColocatePlanTest.java
+++ b/fe/fe-core/src/test/java/org/apache/doris/planner/ColocatePlanTest.java
@@ -186,4 +186,23 @@ public class ColocatePlanTest {
         Assert.assertTrue(isColocateFragment1);
     }
 
+    // Fix #8778
+    @Test
+    public void rollupAndMoreThanOneInstanceWithoutColocate() throws Exception {
+        String createColocateTblStmtStr = "create table db1.test_colocate_one_backend(k1 int, k2 int, k3 int, k4 int) "
+                + "distributed by hash(k1, k2, k3) buckets 10 properties('replication_num' = '1');";
+        CreateTableStmt createColocateTableStmt = (CreateTableStmt) UtFrameUtils.parseAndAnalyzeStmt(createColocateTblStmtStr, ctx);
+        Catalog.getCurrentCatalog().createTable(createColocateTableStmt);
+
+        String sql = "select a.k1, a.k2, sum(a.k3) "
+                + "from db1.test_colocate_one_backend a join[shuffle] db1.test_colocate_one_backend b on a.k1=b.k1 "
+                + "group by rollup(a.k1, a.k2);";
+        Deencapsulation.setField(ctx.getSessionVariable(), "parallelExecInstanceNum", 2);
+        String plan1 = UtFrameUtils.getSQLPlanOrErrorMsg(ctx, sql);
+        Assert.assertEquals(2, StringUtils.countMatches(plan1, "AGGREGATE"));
+        Assert.assertEquals(5, StringUtils.countMatches(plan1, "PLAN FRAGMENT"));
+
+    }
+
+
 }