Abstract: Photovoltaic power generation is intermittent and uncertain,and the output characteristics of photovoltaic cells are largely affected by irradiance and temperature. In order to improve the efficiency of photovoltaic power generation and system stability,it is necessary to stabilize the output power of photovoltaic array at the set value through maximum power point tracking（MPPT）technology.However,the actual environment is complex and changeable.Under partial shadow conditions,the traditional MPPT control cannot effectively track the maximum power point（MPP）.Based on the analysis of the output characteristics of photovoltaic cells,a MPPT algorithm based on improved particle swarm optimization（PSO）was proposed to dynamically change the inertia weight and realize the optimal tracking of the MPP.The simulation results of traditional MPPT algorithm and MPPT control based on improved PSO were compared to verify the superiority of improved PSO algorithm in MPPT under complex environment.The simulation results show that the PSO photovoltaic system output power tracking speed and accuracy are better than traditional MPPT algorithm,which have great practical significance for improving the efficiency of photovoltaic cells.