Based on the data of microwave radiometer, automatic station and Zhangjiakou Radiosonde from 22 January to 30 March 2019 in the Genting Venue of Winter Olympic Games, the accuracy of retrieved temperature and humidity profile was analyzed, and the characteristics and causes of night heat and water vapor were discussed in combination with the 6 h reanalysis data of NCEP/NCAR. The results show that the temperature and water vapor density retrieved by microwave radiometer have a good correlation with the observations by radiosonde and automatic stations, but that of the relative humidity is slightly poor. The mean error (ME) of temperature retrieved by microwave radiometer is relatively small at all levels, and the availability is strong; the root mean squared error of water vapor density are relatively large near the ground, and decrease with the increase of height; the ME of relative humidity at all levels is large, and the maximum reaches 25%. In addition, cloud and precipitation cause the error of temperature and water vapor density to increase at most heights, but the error of relative humidity with precipitation, at most altitudes, is obviously smaller than that under conditons of clear sky and cloud. Further study on the characteristics of heat and water vapor at night shows that the inversion layer structure at night is very common in the Genting Venue, with a probability of 50%. The inversion layer top is generally near or below the mountain top. When combined with warm advection, the thickness and temperature difference of inversion layer will be greatly enhanced. The warm advection and the subsidence movement in the middle and lower layers behind the cold front may bring obvious night temperature increasing to the venue. In the process of temperature increasing dominated by subsidence movement, the profile of microwave radiometer shows that the temperature in the middle and lower layers increases as a whole, and the water vapor density in the lower layers decreases obviously under the effect of subsidence and divergence. In the warming process dominated by warm advection, the warming intensity decreases with height, and the warming process shows obvious humidification phenomenon.