This paper makes a comparative study of the operations management of our machine tool industry with Data Envelopment Analysis method.8-input and 4-output variables are used to carry out a comprehensive assessment on 66 machine t0ol factories. The analysis shows 34 of them are relatively efficient, but 11 of them have low efficiency.The DEA method is used to analyze the returns of scale under current technical conditions and obtain the mean values of the most productive scale size(MPSS).The study shows DEA method is a promising technique for systems assessment, its application has bright prospects.