Abstract: The HTG-4 microwave radiometer data were used to analyze the three important weather processes in the winter of Chengdu Shuangliu Airport from 2018 to 2020. The results show that the microwave radiometer data can reflect the vertical characteristics and trends of the atmosphere under three weather conditions of fog, frost and ice. The temperature data and the liquid water path LWP have a strong monitoring and early warning effect on the generation and dissipation of fog. The water vapor density can help forecasters understand the environmental field conditions of fog in advance and the atmospheric temperature data can detect the generation and dissipation of the inversion layer. The high value area of relative humidity ( relative humidity ≥ 85% ) can be used to determine whether there is cloud. The surge of liquid water path LWP corresponds to the increase of fog concentration, but it has been at a low value in frost weather. The combination of liquid water profile LPR and atmospheric temperature-humidity profile can predict or detect the icing position in the air, that is, when the atmospheric temperature layer is between −10°C and 0°C, and in the high humidity area and the large value area of liquid water content. It is easy to cause aircraft icing.