Abstract: In view of the loss of transmission and distribution cost of power grid enterprises caused by local accommodation of distributed generators, and the current formulation mechanism of transmission and distribution prices can not truly reflect the actual utilization of the distribution network by distributed generators in the mode of “surplus power sent to power grid”, this paper proposes a network fee mechanism design for the distribution network based on the multi-stage investment planning with networksource cooperation. First, according to the load growth situation, taking the investment year and capacity as the decision variables, the planning cycle of distributed generators is divided into several stages. On this basis, the network fee corresponding to each stage is calculated by using the proposed network fee model. The multi-stage planning model with source-network cooperation aims to maximize the main benefits of investors of distributed generators and minimize the loss and voltage fluctuation of the distribution network. The calculation model of network fee is based on key influencing factors, such as the occupation of transmission and distribution assets, the voltage level, and the electrical distance of market-based distributed generation trading. The network fee of distributed generators is constructed, which includes the basic charge, the congestion surcharge, and the cross-subsidy charge. The simulation results show that the proposed network fee mechanism combined with the distributed generator investment planning can guarantee the benefits of the investors and the asset recovery of the distribution network, and can improve the penetration and accommodation rate of distributed generators to a certain extent.