As the problem of smog becomes more and more prominent in the northern part of China, "coal-to-electricity" has received extensive attention. How to scientifically evaluate its comprehensive benefits is worthy of further study. Therefore, based on the principal component analysis method, a model for evaluating the comprehensive benefits of the “coal-to-electricity” project is proposed in this paper. A comprehensive benefit evaluation index system is constructed by comprehensively considering environmental protection benefits, social benefits, and economic benefits. On this basis, based on all the evaluation indicators, the main component factors are stripped out, and the comprehensive benefit evaluation of different “coal to electricity” schemes is realized. Five "coal-to-electricity" projects implemented in different regions are taken as examples for analysis. The results show that the proposed model can effectively and objectively evaluate the comprehensive benefits of "coal to electricity" project on the premise of minimizing the overall calculation workload, which provides guidance and reference for the implementation of "coal to electricity" project.