Abstract: Based on multi-source data such as ERA5 reanalysis data and conventional meteorological data, the “Top-Down-Approach” precipitation phase analysis method was used to analyze the snowfall process at Shuangliu Airport on January 16, 2023, focusing on the prediction of precipitation phase. The results show that: (1) The temperature layer of −12°C~−16°C with humidity greater than 85% is conducive to the formation of dendritic snowflakes. In addition, the high concentration and overlapping areas of ice phase particles and water phase particles in clouds are conducive to the formation of snowflakes with low melting ratio. (2) Lower wet bulb 0 °C temperature zone (WBZ) conditions may appropriately reduce the limit of the ground temperature in the snowfall forecast. (3) Combined with the temperature profile, the liquid water profile product of the microwave radiometer can indicate the main distribution height of the ice-producing clouds, and the liquid water content will increase significantly before the snowfall process starts, and decrease in advance when the snowfall tends to end, which has certain indicative significance for snowfall process.