In order to investigate the flow characteristics of water in cabin fish tanks under the condition of swaying at sea, a bottom push flow separated simulated tank culture system was designed. The system was mainly composed of aquaculture facilities and equipment such as isolation net laid 1m from the bottom of the tank and four push flow pumps placed below the isolation net. By analyzing the influence of different bottom pushing flows on water quality indexes such as ammonia nitrogen mass concentration and turbidity of the test system, the appropriate bottom pushing flow was obtained, and the verification experiment was carried out with this parameter, and compared with the control tank with high water exchange capacity. The results show that the removal effect of ammonia nitrogen mass concentration in the surface and bottom water of the test tank was positively correlated with the bottom push flow. When the bottom push flow reached 160 m3/h, the best removal effects were achieved, reaching 68.02% and 58.68% respectively. During the farming period of more than one month, there was no significant difference in ammonia nitrogen mass concentration, turbidity, water color and other water quality indexes between the test tank, which had an inlet flow of 40 m3/h and a 160 m3/h capacity bottom push flow pump turned on for 1h whenever feeding started, and the control tank with an inlet flow of 120 m3/h without bottom push flow. The results show that the designed system can also achieve ideal water quality control effects even when the inlet flow is reduced by about 70%. This cabin bottom push flow culture simulation system could provide reference for the follow-up exploration and optimization of fish culture cabins suitable for complex offshore conditions and the construction of large-scale marine industrial ship culture mode.