The large-scale integration of distributed photovoltaic (DPV) into distribution networks brings significant low-carbon benefits, but also poses new challenges to the safe and economic operation of distribution networks. As the direct carrier of DPV grid connection, distribution networks need to balance system security, operational economy and low-carbon emission reduction in the planning process, and the access location and capacity of DPV directly affect the realization of these goals. Therefore, how to scientifically plan the access scheme of DPV from the perspective of distribution networks to maximize its comprehensive benefits has become a key issue that needs to be urgently addressed. To this end, this paper proposes a DPV siting and sizing planning model aimed at maximizing the comprehensive benefits of distribution networks. Firstly, Latin hypercube sampling (LHS) and fast forward elimination techniques are used to handle the randomness of DPV output and generate typical output scenarios. Secondly, the investment return of DPV independent power producers (DPV-IPP) is taken as the economic evaluation index, and a comprehensive benefit model of distribution networks including annual grid loss profit and loss, annual voltage quality profit and loss and annual carbon emission reduction benefits is established. The genetic algorithm is used to solve the above model and jointly optimize the location and capacity of DPV. Finally, a case study is conducted on the IEEE-33 node distribution system to verify that the model can provide a scientific decision-making basis for distribution network operators in DPV planning.