Aiming at the shortage of invariable weight of the traditional effectiveness evaluation, a dynamic evaluation method is proposed based on variable weight and grey target theory. This method can solve the multi-attribute effectiveness evaluation problem of the command and control system. First, the concept of index action degree is introduced to solve the relative importance problem of the attribute value of the mixed index, and the improved G1 method is used to solve the initial constant weight of the index. Secondly, a new dominance function using the relative distance between the index and the target as the variable is defined to characterize the advantages and disadvantages of indexes. Local state variable weight function based on the initial constant weight is constructed to correct initial constant weight. Finally, with the projection target distance as a measure, the comprehensive effectiveness and sorting of evaluation objects are determined by using the projective grey target method. A case study is used to illustrate the feasibility of the proposed method.