In order to improve the efficiency of hot washing and finish the work better, the simulation research was done by fluid simulation software FLUENT. The hitting force characteristics of three typical nozzles under different inlet pressure and target distance were analyzed. The influence of flushing angle on cleaning efficiency and the relationship between the hitting force and the flow rate as well as the power were analyzed. The results show that the hitting force increased with the increase of inlet pressure, and decreased with the increase of the target distance.Washing angle will change the jet characteristics, and affecting the cleaning effect. Enhancing the hitting force by increase the inlet pressure is more economical than increase the nozzle diameter.