Due to the limitation of cabin space, FPSO domestic water pipe network system has the characteristics of long water delivery distance, more bending of pipeline and frequent opening and closing of valves, etc. The above characteristics are very likely to cause water hammer in the pipeline, resulting in increased risk of safe operation of pipe network system. In this paper, a FPSO domestic water system was taken as the research object. In view of the water hammer problem in the pipe network system, the model of FPSO domestic water system was established by using dynamic fluid analysis software AFT-Impulse, combined with the factors affecting the water hammer phenomenon (such as pipe diameter, velocity of wave, pipe length, pipeline roughness and valve closing time), the steady state analysis and transient analysis of multi-working conditions and multi-scenarios were realized to determine the main control factors. Based on the influence of main control factors, a comparison scheme of water hammer protection in FPSO domestic water system was proposed. Through the transient analysis of AFT-Impulse software under multi-working conditions, the optimal scheme of water hammer protection for FPSO domestic water system was obtained, which provided guarantee for the safe operation of the system.