The cultivation of the scientific research ability of postgraduates is the key factor to judge the quality of training on postgraduates in China, and the core element to promote the cultivation of high-quality talents and the development of high-tech in China. Therefore, by means of questionnaire survey, factor analysis and target analysis, the paper is committed to constructing the evaluation system of the scientific research ability of postgraduates and establishing the weight of index to make the scientific evaluation of their ability in scientific research. It aims to help teaching and research workers in university, management authorities and individuals establish a more scientific and reasonable model of postgraduate training.