At present, the method of visual judgment based on standard pattern is mainly used to analyze the shape of the leading and trailing edges of the processed blades. There are some problems such as low measuring efficiency, poor repeatability and inconsistent evaluation results. In this paper, a method for judging the shape of the leading and trailing edges based on the trend of thickness deviation is presented. The blade edge thickness is divided by the arc of the blade section. According to the maximum thickness deviation, the maximum thickness deviation ratio and the variation coefficient of thickness deviation in the evaluation area, the shape of the cutting edge of the leading and trailing edges of the blade is automatically analyzed. This method has fast and accurate characteristics and provides an important guarantee for the evaluation of engine blade processing quality.