diff --git a/src/core/steps/data_preparation_step.py b/src/core/steps/data_preparation_step.py
index 4792414..e0b6ef7 100644
--- a/src/core/steps/data_preparation_step.py
+++ b/src/core/steps/data_preparation_step.py
@@ -96,6 +96,19 @@ class DataPreparationStep:
         if final_boundary_path is None and water_mask_path is not None:
             final_boundary_path = water_mask_path
 
+        # 【新增安全防护】智能拦截矢量 .shp，强制替换为步骤 1 生成的栅格 .dat
+        if final_boundary_path and str(final_boundary_path).lower().endswith('.shp'):
+            # 向上追溯查找 1_water_mask 目录下的 dat 替身
+            possible_dat = Path(deglint_img_path).parent.parent / "1_water_mask" / "water_mask_from_shp.dat"
+            if not possible_dat.exists() and output_path:
+                possible_dat = Path(output_path).parent.parent / "1_water_mask" / "water_mask_from_shp.dat"
+
+            if possible_dat.exists():
+                print(f"💡 智能拦截：检测到输入掩膜为矢量 .shp，自动切换为已生成的栅格掩膜: {possible_dat}")
+                final_boundary_path = str(possible_dat)
+            else:
+                print(f"⚠️ 警告：检测到输入掩膜为 .shp 且未找到对应 .dat 替身，可能导致底层读取失败。")
+
         flare_path = glint_mask_path
         if flare_path:
             print(f"光谱提取使用耀斑掩膜: {flare_path}")
diff --git a/src/utils/band_math.py b/src/utils/band_math.py
index b5678a8..8e20a9d 100644
--- a/src/utils/band_math.py
+++ b/src/utils/band_math.py
@@ -96,8 +96,14 @@ class BandMathCalculator:
 
             print(f"计算表达式: {calc_expression}")
 
-            # 安全地计算表达式
-            result = eval(calc_expression)
+            # 【新增安全防护】引入 numpy 命名空间，让 eval 引擎安全识别 nan 与 inf
+            import numpy as np
+            try:
+                # 即使 calc_expression 含有纯字符 nan，也能被 np.nan 安全接管
+                result = eval(calc_expression, {"__builtins__": None}, {"nan": np.nan, "inf": np.inf, "np": np})
+            except Exception as e:
+                print(f"⚠️ 警告：公式计算异常 ({e})，该点赋值为 nan")
+                result = np.nan
 
             # 返回结果
             if var_name: