Abstract:After the completion of the ship hydraulic system, trim balance system and other pressure pipelines conveying liquid, the valve is suddenly closed with transient flow phenomena and strong noise in the pipeline. This phenomenon is disadvantage to the stable and safe navigation of the ship and the comfortable life of the crew. During the water transfer process of the trim balance system, the transient flow phenomenon in the ship pressure pipeline is the most prominent. Therefore, due to the operation principle of the trim balance system, a test bench was built for the ship trim balance system, and the influence regular tests of water hammer phenomenon were conducted. The test results show that the test bench can effectively simulate the water hammer phenomenon in the water transfer process of the ship trim balance system, and the influence rules of water transfer pressure, valve driving pressure, pipeline restraint mode, and FFT analysis on the water hammer phenomenon are acquired.