Using the 3-D convective storm numerical model(IAP-CSM3D),dynamical effects by means of artificial updraft restraint are introduced into some regions of modeling convective clouds during a short time period at different evolution stages and different areas of a hailstorm,to study physical processes which affect the precipitation formation of hailstorm.The results indicate that in the earlier stage of the development of a hailstorm,an artificial restraint with a common intensity can highly influence the development and precipitation of the hailstorm,increasing its surface precipitation,especially the hailfall amount,but in the later stage of the hailstorm development,the restraint has a small influence on the precipitation.When the restraint is quite strong and its range is very large,only at the vigorous stage the restraint can distinctively reduce the hailfall amount and other solid-state precipitation from the affected hailstorm.Finally,the mechanism for the effect of the updraft restraint of the hailstorm on micro-physical processes is analyzed.