diff --git a/painter.js b/painter.js
index 32cc760..7a11ff4 100644
--- a/painter.js
+++ b/painter.js
@@ -851,7 +851,7 @@ function setStringPrototype(screenK, scale) {
     const formula = /^calc\((.+)\)$/.exec(this);
     if (formula && formula[1]) {
       // 进行 calc 计算
-      const afterOne = formula[1].replace(/([^\s]+)\.(left|right|bottom|top|width|height)/g, word => {
+      const afterOne = formula[1].replace(/([^\s\(\+\-\*\/]+)\.(left|right|bottom|top|width|height)/g, word => {
         const [id, attr] = word.split('.');
         return penCache.viewRect[id][attr];
       });