diff --git a/src/observer/storage/index/bplus_tree.cpp b/src/observer/storage/index/bplus_tree.cpp
index aa63c63c7..aca159f54 100644
--- a/src/observer/storage/index/bplus_tree.cpp
+++ b/src/observer/storage/index/bplus_tree.cpp
@@ -312,7 +312,8 @@ RC LeafIndexNodeHandler::move_to(LeafIndexNodeHandler &other)
   other.append(__item_at(0), this->size());
   other.set_next_page(this->next_page());
 
-  RC rc = mtr_.logger().node_remove_items(*this, 0, span<const char>(__item_at(0), this->size() * item_size()), this->size());
+  RC rc = mtr_.logger().node_remove_items(*this, 0, span<const char>(__item_at(0), static_cast<size_t>(this->size()) * static_cast<size_t>(item_size())), this->size());
+
   if (OB_FAIL(rc)) {
     LOG_WARN("failed to log shrink leaf node. rc=%s", strrc(rc));
   }
@@ -324,7 +325,7 @@ RC LeafIndexNodeHandler::move_to(LeafIndexNodeHandler &other)
 // 复制一些数据到当前节点的最右边
 RC LeafIndexNodeHandler::append(const char *items, int num)
 {
-  RC rc = mtr_.logger().node_insert_items(*this, size(), span<const char>(items, num * item_size()), num);
+  RC rc = mtr_.logger().node_insert_items(*this, size(), span<const char>(items, static_cast<size_t>(num) * static_cast<size_t>(item_size())), num);
   if (OB_FAIL(rc)) {
     LOG_WARN("failed to log append items. rc=%d:%s", rc, strrc(rc));
     return rc;