Using the observation data of micro rain radar, raindrop disdrometer and rain gauge at Jingyu Station, Jilin Province, from 24 to 25 August 2021, the vertical distribution of raindrop size and the evolution of microphysical characteristic parameters in a mixed cloud precipitation process at Changbai Mountain are analyzed. The results show that the rainfall variation trend with high resolution of 150 m retrieved by micro rain radar and the ground rainfall measured by raindrop disdrometer and rain gauge are basically consistent, but there are some deviations between the observed values and inversion values. The Gamma function goodness of fit clocks up 0.99 for the ground raindrop size distribution, which is better than that of micro rain radar. In addition, the fitting value for number concentration of large raindrops (D>3.0 mm) retrieved by micro rain radar is significantly smaller. Research also shows that raindrops in different diameters have different contributions to microphysical parameters at different heights. For small raindrops (D≤1.0 mm), its contribution rate to rainfall intensity, reflectivity factor, liquid water content, and total number concentration decreases generally with lowering height. However, the contribution rate of medium raindrops （1.0 mm＜D≤3.0 mm） and large raindrops to these parameters increases as height declines. Besides, the evaporation and coagulation effects of raindrops show varieties in different precipitation stages. In the early precipitation stage, the evaporation effects of raindrops is stronger due to higher temperature and lower relative humidity in the falling process of raindrops. In the stage of concentrated precipitation, the coagulation effect of raindrops is more evident with the relative humidity approaching saturation.