Abstract: Large-scale distributed generation connecting to the distribution network will cause the problem of voltage overshoot, which requires additional configuration of reactive power compensation equipment. Meanwhile, different permeability of distributed power supply access and different photovoltaic-wind ratio will also affect the voltage overshoot degree of the distribution network. Considering the voltage regulation capability of distributed photovoltaic power source, this paper proposes a new optimal allocation model of reactive power compensation for distribution network, which uses distributed photovoltaic power generation as reactive power regulation equipment to participate in the voltage regulation of distribution network, so as to reduce the allocation of additional reactive power compensation equipment. Firstly, the reactive power compensation capability of distributed PV under normal operation and reasonable light abandonment is analysed respectively. On this basis, the optimal allocation model of distribution network reactive power compensation is constructed with the goal of minimizing the loss cost and reactive power compensation equipment allocation cost. Finally, an example of distribution network with different permeability and different distribution wind access ratio is constructed to verify the effectiveness of the optimization model.