In recent years, power grid companies continue to increase investment in distribution network, but there is a lack of a scientific and reasonable distribution network investment benefit evaluation method. Firstly, a two-layer distribution network investment evaluation index system is constructed from the aspects of equipment level, power supply capacity, loss reduction and power consumption increase.Then, the weight of each evaluation index was calculated by the comprehensive analytic hierarchy process (AHP) and entropy method, and the correlation of each evaluation index was reduced by principal component analysis (PCA). Finally, TOP SIS is used to comprehensively evaluate the merits and demerits of each object. Through this research, the investment benefit of distribution network can be evaluated comprehensively, and then the construction and transformation of distribution network system can be guided to realize the maximization of investment benefit.