A reactive power optimization algorithm for distribution network with photovoltaic(PV) generation is proposed to address the problems of power quality degradation, system active power losses increase and system instability caused by the connection of PV generation. Firstly, a multi-objective reactive power optimization model is established with the objective functions of minimizing system active power losses, controllable loads reduction, and PV active power reduction. Secondly, the PV power generation system is modeled mathematically. Thirdly, using the non-dominated sorting genetic algorithm(NSGA-III) to solve the model. Finally, the feasibility and validity of the proposed method are verified by the simulation with the modified IEEE123-bus system.