diff --git a/src/modules/form.js b/src/modules/form.js
index 228dc1d6..0d6a713d 100644
--- a/src/modules/form.js
+++ b/src/modules/form.js
@@ -277,10 +277,11 @@ layui.define(['lay', 'layer', 'util'], function(exports){
               value: ['up', 'down'],
               split: true,
               className: 'layui-input-number',
-              disabled: disabled, // 跟随输入框禁用状态
+              disabled: othis.is('[disabled]'), // 跟随输入框禁用状态
               click: function(elem){
                 var index = $(this).index();
                 var value = elem.val();
+                var rawValue = value;
                 var step = Number(elem.attr('step')) || 1; // 加减的数字间隔
                 var min = Number(elem.attr('min'));
                 var max = Number(elem.attr('max'));
@@ -294,11 +295,15 @@ layui.define(['lay', 'layer', 'util'], function(exports){
                 if(value < min) value = min;
                 if(value > max) value = max;
 
-                // 小数点后保留位数
-                var fixed = function(step){
-                  var decimals = (step.match(/\.(\d+$)/) || [])[1] || '';
+                // 获取小数点后位数
+                var decimals = function(step){
+                  var decimals = (step.toString().match(/\.(\d+$)/) || [])[1] || '';
                   return decimals.length;
-                }(step.toString());
+                };
+
+                // 位数比较
+                var fixed = Math.max(decimals(step), decimals(rawValue));
+
                 if(fixed) value = value.toFixed(fixed);
 
                 elem.val(value);