Based on the cold and high-latitude climate conditions of Hohhot region,two identical flat-plate heat pipe solar collector systems were constructed,and the effects of solar radiation intensity,heat transfer medium flow rate,collector panel surface dust accumulation and other factors on the instantaneous thermal efficiency of the collectors as well as the thermal performance of the system were compared and analyzed through experiments.The results show that,under the same external conditions,the thermal efficiency of the collector increases with the increase of working fluid flow.The change trend of thermal efficiency is similar to that of solar radiation intensity.With the increase of dust density,the dust accumulation on the surface of the collector plate leads to the decrease of the heat gain of the system and the decrease of the collector performance.