Abstract: Abstract: Low power generation efficiency is one of the main obstacles to apply PV (photovoltaic) modules in large scale, and therefore studying the influence factors is of great significance. This article has independently developed a kind of automatic dedusting system of PV modules, which has the advantage of simple structure, low installation cost, reliable operation, without the use of water in the ash deposition, continuous and effective dedusting. The system has been applied to 3 kinds of occasions, including supplying power separately by the PV conversion cell with temperature in the range of -45℃?35℃, having various experimental tests of the assemble angles by the PV module cells and a large area of the PV power system. The dedusting effect of the automatic dedusting system is tested with temperature in the range of -10℃?5℃ when applied in the power separately by the PV conversion cell. Adopting the automatic dedusting system, the dynamic occlusion in the operation process has been simulated and the influence law of the output parameter for PV modules has been researched; the effect of dedusting has been analyzed under different amounts of the ash deposition; the effect of dedusting changing with the amount of the ash deposition has been summarized, and the opening time and the running period have been determined. The experimental PV modules are placed in outdoor open ground at an angle of 45°for 3, 7, 20 days and the amounts of the ash deposition are 0.1274, 0.2933, 0.8493 g/m2 separately. The correction coefficient of PV modules involved in the experiments is 0.9943. The results show that, when the system is in the horizontal and vertical cycle, the cleaning brush makes the output parameters of the PV modules, including the output power, the electric current and the voltage, change according to the V-shaped law as it crosses a row of battery. Compared with the process of downlink, the output parameters of PV modules in the process of uplink fluctuate more largely. When the dynamic occlusion area is increased by 1.6150%, the low value of power output of PV modules will decline by about 40%; when the automatic dedusting system runs for 1 year in horizontal and vertical direction, the independent PV modules generate energy loss of 1.0241 and 0.8034 kW·h respectively. So the electricity consumption can be neglected in terms of the independent PV modules, however, the electricity consumption of large capacity PV generation system in the process of dedusting can not be neglected. The running process of the system is scheduled to start about 10 min before sunrise and operated once every 3 days according to different regions and seasons; the average output powers of PV modules are increased by 1.5171%, 1.7312% and 9.6021% respectively after dedusting when the ash depositions are collected for 3, 7 and 20 days. The more the amount of ash deposition is, the more obviously the automatic dedusting system runs. The automatic dedusting system can better improve the power generation efficiency of PV modules.