The value of ship impact force is very important when designing lock gates or adding anti-collision facilities. Taking Jianbi triangular lock as an example，we use ANSYS finite element calculation software to analyze the time-history curves of the impact force of 25 working conditions under 5 kinds of impact velocity and 5 kinds of ship displacement，and compare the results with the common domestic codes. The results show that the impact time decreases with the increase of impact velocity and increases with the increase of ship tonnage. The impact forces adopted in Code for Design of Hydraulic Structures of Shiplocks and Code for Design of Lock Gates and Valves of Shiplocks do not comprehensively consider the influence of ship tonnage and impact velocity，and the values are too low. The value of ship impact force in Design Specification for Steel Gates of Water and Hydropower Projects is about 0.7 times as the average value of the impact force in finite element analysis.