Abstract: In photovoltaic (PV) power generation, the influence of snow covering on irradiance is very significant, and it directly affects the power generation of the photovoltaic arrays. By designing a targeted test plan, an outdoor empirical test was carried out to study the influence of snow thickness on the receiving irradiance of the PV array plane, and the factors affecting the snow melting rate on the PV array surface were analyzed. The results show that the loss of irradiance of PV array increased sharply with the increase of snow thickness. The snow melting rate on the PV array surface was mainly affected by the structure and power density of the PV modules. In the north, especially in areas with heavy snowfall or high snowfall in winter, it is necessary to consider the selection of PV modules according to local climatic conditions, or take appropriate measures to reduce snow covering time in order to reduce power generation loss and increase power generation revenue.