Abstract: The quality evaluation of equipment in service phase was studied under the condition of fuzzy and uncertain influencing factors, and a quantitative evaluation algorithm based on Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) was proposed. The quality characteristics and influencing factors of equipment in service stage were analyzed. Based on TOPSIS, a quality evaluation model of the missile equipment in service stage was established by using the approximate positive and negative ideal points and the principle of grey correlation degree. The evaluation algorithm was given, the grey correlation degree was calculated and the evaluation coefficient was obtained. The example shows that the grey correlation degree evaluation algorithm based on TOPSIS can effectively solve the ranking problem among the evaluation objects, and the evaluation conclusion is less affected by subjective factors, and is in line with the actual military equipment support, and has strong operability, so it can effectively evaluate the quality of equipment in service stage.