The study of fuzzy cluster analysis is mainly the classification of samples. In this paper, the fuzzy clustering method is used to classify the defects of software, and the method of attribute weight calculation is introduced. The similarity of defect data is analyzed with the method of attribute proximity in data mining. According to the category of attributes, it does not only reflect the degree of similarity between the attributes of the defect data, but also reflects the distance between the attributes. In this paper, the software defect data are analyzed and compared with the measurement results. The experimental results show that the improved fuzzy clustering similarity measurement method has somehow improved in classification accuracy.