diff --git a/be/src/pipeline/exec/scan_operator.cpp b/be/src/pipeline/exec/scan_operator.cpp
index 3af8aa1b3a4bb1..2f21b1626a5e88 100644
--- a/be/src/pipeline/exec/scan_operator.cpp
+++ b/be/src/pipeline/exec/scan_operator.cpp
@@ -1224,7 +1224,8 @@ Status ScanLocalState<Derived>::_start_scanners(
     auto& p = _parent->cast<typename Derived::Parent>();
     _scanner_ctx = PipXScannerContext::create_shared(
             state(), this, p._output_tuple_desc, p.output_row_descriptor(), scanners, p.limit(),
-            state()->scan_queue_mem_limit(), _scan_dependency);
+            state()->scan_queue_mem_limit(), _scan_dependency,
+            p.ignore_data_distribution() ? 1 : state()->query_parallel_instance_num());
     return Status::OK();
 }
 
diff --git a/be/src/vec/exec/scan/pip_scanner_context.h b/be/src/vec/exec/scan/pip_scanner_context.h
index e33523cf3bf710..e93e9956ff4096 100644
--- a/be/src/vec/exec/scan/pip_scanner_context.h
+++ b/be/src/vec/exec/scan/pip_scanner_context.h
@@ -47,9 +47,11 @@ class PipXScannerContext final : public vectorized::ScannerContext {
                        const RowDescriptor* output_row_descriptor,
                        const std::list<std::shared_ptr<vectorized::ScannerDelegate>>& scanners,
                        int64_t limit_, int64_t max_bytes_in_blocks_queue,
-                       std::shared_ptr<pipeline::Dependency> dependency)
+                       std::shared_ptr<pipeline::Dependency> dependency,
+                       const int num_parallel_instances)
             : vectorized::ScannerContext(state, output_tuple_desc, output_row_descriptor, scanners,
-                                         limit_, max_bytes_in_blocks_queue, 1, local_state) {
+                                         limit_, max_bytes_in_blocks_queue, num_parallel_instances,
+                                         local_state) {
         _dependency = dependency;
     }
 
diff --git a/be/src/vec/exec/scan/scanner_context.cpp b/be/src/vec/exec/scan/scanner_context.cpp
index 2ed0df998b49f4..cf1dd24641d4fb 100644
--- a/be/src/vec/exec/scan/scanner_context.cpp
+++ b/be/src/vec/exec/scan/scanner_context.cpp
@@ -78,7 +78,6 @@ ScannerContext::ScannerContext(RuntimeState* state, const TupleDescriptor* outpu
                               : config::doris_scanner_thread_pool_thread_num /
                                         (_local_state ? num_parallel_instances
                                                       : state->query_parallel_instance_num());
-    _max_thread_num *= num_parallel_instances;
     _max_thread_num = _max_thread_num == 0 ? 1 : _max_thread_num;
     _max_thread_num = std::min(_max_thread_num, (int32_t)scanners.size());
     // 1. Calculate max concurrency