Abstract: From April 2 to 4,2023,the spring rain and snow occurred in central Inner Mongolia with the widest range,longest duration and highest intensity in the past 60 years.The characteristics of the multi-source data during the rain and snow process were analyzed by using the observation data of meteorological stations,satellite inversion cloud products,millimeter wave cloud detector,microwave radiometer,wind profile radar,particle spectrum and other observation data.The results show that the concentrated precipitation begins when the near-surface wind changes from southwest wind to easterly wind observed by wind profile radar,while the temperature drops faster the closer the surface is to the surface observed by microwave radiometer,indicating the formation of a cold mat at the lower level.The vertical wind profile directly reflects the process of the cold mat thickening and the southwest warm and wet air climbing along the cold mat,and the cold mat leads to the rapid transition of rain and snow phase and the long duration of precipitation.Cloud thickness,echo intensity and cloud density observed by millimeter-wave cloud detector are positively correlated with precipitation efficiency.The jump in cloud optical thickness and liquid water path values retrieved by FY-2G satellite has indicative significance for precipitation intensity increase,and the peak appearance time of cloud parameters is earlier than the peak appearance time of precipitation.The surge of water vapor and liquid water in the air observed by microwave radiometer has a strong indication of precipitation occurrence,and the liquid water is more sensitive.The particle spectrum distribution shows that the maximum particle size of raindrop is smaller than that of sleet,and the particle falling velocity increases with the particle size increasing,but decreases with the particle number increasing.