The leakage of the pipeline valve will affect the waveform and attenuation characteristics of the transient pressure wave, therefore the transient flow method could be used to detect the leakage of the valve in the pipeline. In this paper, the Flowmaster fluid simulation software is used to set up a typical ship pipeline valve system model. The effect of pipeline valve leakage on transient pressure wave in pipe is simulated numerically. The influence of the opening degree of leakage valve, velocity and pressure on the transient pressure wave in the tube is studied. On this basis, the main work that should be carried out in the next step is put forward. This can be used to detect the leakage status of pipeline valves, and to improve the performance of pipeline valves. It is of great significance to ensure the operational safety of warships and ensure the effectiveness of warships.