diff --git a/src/postprocessing/map.py b/src/postprocessing/map.py
index a939555..375c4cb 100644
--- a/src/postprocessing/map.py
+++ b/src/postprocessing/map.py
@@ -730,21 +730,21 @@ class ContentMapper:
                 by_min = y_min + iy * block_dy
                 by_max = y_min + (iy + 1) * block_dy
 
-                # 带缓冲区的搜索范围
-                search_xmin = bx_min - window_size
-                search_xmax = bx_max + window_size
-                search_ymin = by_min - window_size
-                search_ymax = by_max + window_size
-
-                # 缓冲区内的网格点索引
-                grid_mask_x = (grid_x >= search_xmin) & (grid_x <= search_xmax)
-                grid_mask_y = (grid_y >= search_ymin) & (grid_y <= search_ymax)
+                # 块自身的网格（不含缓冲，保证每个网格点只被计算一次）
+                grid_mask_x = (grid_x >= bx_min) & (grid_x <= bx_max)
+                grid_mask_y = (grid_y >= by_min) & (grid_y <= by_max)
                 if not np.any(grid_mask_x) or not np.any(grid_mask_y):
                     continue
 
                 sub_grid_x = grid_x[grid_mask_x]
                 sub_grid_y = grid_y[grid_mask_y]
 
+                # 带缓冲区的搜索范围（仅用于筛选采样点）
+                search_xmin = bx_min - window_size
+                search_xmax = bx_max + window_size
+                search_ymin = by_min - window_size
+                search_ymax = by_max + window_size
+
                 # 缓冲区内的采样点
                 point_mask = (
                     (points[:, 0] >= search_xmin) & (points[:, 0] <= search_xmax) &