With the continuous advancement of facility agriculture, the application of solar greenhouses in northern China is becoming increasingly popular, and double-film solar greenhouses, as an effective agricultural facility, have significantly improved the crop growth environment. This study focuses on double-layered film solar greenhouses in cold and arid northern regions under frigid weather conditions. January 21st and 22nd, the two days with the lowest average temperatures in January 2024, were taken as the research object, and the thermal insulation performance of the greenhouse and the temporal and spatial variation of the internal thermal and humid environment under severe cold weather conditions were discussed through the analysis of its internal thermal and humid environment. The study shows that the double-film solar greenhouse can maintain a relatively stable indoor temperature and humidity in the severe cold weather after heavy snowfall, which greatly improves the growth environment of winter crops. The internal temperature of the double-film solar greenhouse showed three stages, including the heating stage accompanied by the rising sun, the rapid cooling stage after noon, and the slow cooling stage at night. The warming phase accompanied by the rise of the sun gradually decreased from east to west along the east-west length direction, from south to north along the north-south span direction, and gradually decreased from high to low along the vertical height direction. In the slow cooling stage after noon, the temperature gradually decreased from west to east along the east-west length direction, from north to south along the north-south span direction, and gradually decreased from low to high along the vertical height direction. Relative humidity also showed a three-stage periodic variation law, and the specific change was negatively correlated with the temperature variation law. The spatial distribution of soil temperature decreasing from the middle to the east and west along the length direction also showed a decreasing spatial distribution. The span direction decreased from the middle to the north and south, and the temperature of the north wall area was higher than that of the southern front foot. In the vertical direction, the temperature fluctuation decreased with the increase of depth，indicating that the underlying soil had stronger thermal stability. The results show that the double-film solar greenhouse can also keep the planting area not lower than 3.61 ℃ in extreme weather, and the stable cultivation conditions of the ambient temperature of the planting area higher than 5 ℃ in winter. The results of this study further reveal the characteristics of the hot and humid environment of the double-film solar greenhouse under severe cold weather conditions, and provide a scientific basis and data support for the precise regulation of environmental factors in the greenhouse.