The power generation characteristics of photovoltaic modules are of great significance to optimize the power generation efficiency of photovoltaic power generation system. The generation characteristics of photovoltaic module are commonly obtained from theoretical simulation, which are different from the characteristics obtained from practical application. The calculation model of photovoltaic module power generation characteristics is established by using lighting sensors and temperature sensors to collect environmental parameters, galvanometer and voltmeter to detect parameters such as photo-generated current, reverse cutoff current, open circuit voltage and so on. Accurate testing of power generation characteristics of photovoltaic modules is achieved. The power generation characteristic curves of output voltage-output current and output power-output voltage under different environmental parameters are got. The simulation and engineering tests show that the photovoltaic power generation system based on the above characteristic curve can achieve better performance when controlling the maximum power, and the error between theoretical value and practical value is less than 1%.