In this paper, anaxis-symmetry mode is set up to simulate the high speed liquid-solid impact of 17-4ph material, which is widely used inwet steam turbine bladesof the nuclear power units. The initial speed of the droplet with the diameter of 0.3mm is 400m/s. The deformation of the solid and the stress distribution variation with time are obtained via numerical method. And the variation of the pressure inside the droplet and solid target has also been analyzed in detail. In this case, the maximum pressure in the vertical direction of the solid is 1099MPa, and the maximum deformation distance of the plateis 140nm. The results provide useful supplement and reference to the high-speed liquid-solid impact theory.