This paper presents a new adaptive overcurrent protection for distribution network with high penetration rate of DG, on the basis of the impact of distributed generation connecting to the distribution network. According to fault component network, the equivalent impedance of DG’s back side is calculated, which is integrated with distribution over current protection setting calculation. The main protection and back-up protection setting values are calculated, and the adaptive overcurrent protection scheme is constructed. Simulation results show that, compared with conventional overcurrent protection, the proposed adaptive overcurrent protection can solve the problem of protection scope overreach of overcurrent protection due to DG access to distribution network, so it has a good prospect of engineering application.