An improved G1-CRITIC combination weighting method is proposed to improve the scientific rationality of missile equipment maintenance support effectiveness evaluation index weighting. The maintenance support effectiveness evaluation index system of missile equipment is constructed, which is composed of seven factors, such as human resources, material support, information resources, training and training support. The traditional G1 method is modified by DEMATEL to obtain the subjective weight, and the CRITIC method is improved by introducing the concept of variation coefficient too btain the objective weight. The subisctiys and objective weights are combined by using the minimum discriminant information method. The example results show that the method is reasonable and effective, and it can provide reference for the effectiveness evaluation of missile equipment maintenance support.