Abstract: High-temperature overheating and low-temperature freezing damage are the potential safety hazards of common flat-plate solar collectors. In this paper,a new type of dual-temperature PCM-based flat-plate solar collector was proposed,its construction form was clarified and a three-dimensional physical model was established. Through the analysis,safety performance evaluation indexes such as temperature difference and degree of frost damage were established. The heat storage and release characteristics of the dualtemperature PCM-based solar collector under high and low temperature conditions were analyzed,and the temperature variation of PCMbased solar collector under actual conditions in winter and summer in different regions were studied by dynamic simulation. The results show that in Lhasa area,the dual-temperature PCM-based solar collector can effectively reduce the overheating time about 2 hours,reduce the duration of freezing damage by more than 9 hours,and increase the minimum temperature at night by about 11 ℃.