Abstract: In order to study the effect of pollution discharge system in the seawater system rectangular arc angle aquaculture tank, a physical model test system of single channel blowdown was established in this paper. The effects of the parameters of number of daily water cycle, the incident angle of the inlet pipe, diameter depth ratio and relative arc width ratio on the characteristics of pollutants collected and discharged from aquaculture tank were studied. The rule of solid particles blowdown and the main factors affecting the blowdown effect in the pond were analyzed. In the range of experimental research designed in this paper, the results show that: the number of daily water cycle was the primary factor affecting the sewage discharge effect of single channel rectangular arc angle aquaculture system, the higher the average speed in the tank, the better the sewage discharge effect of the aquaculture system; the single tube arc wall inlet at 20° intervals the condition, the best sewage discharge effect was when the angle of incidence of the inlet pipe is 40°; The obvious boundary diameter-to-depth ratio of solid particulate matter discharge efficiency is 6∶1, and the square arc angle aquaculture tank diameter depth ratio of less than 6∶1 is more conducive to system emission; the square arc angle aquaculture tank sewage effect was significantly better than the square aquaculture tank, and the relative arc width ratio R/B = 0.2 was the best. The finding indicated that, optimizing the structure and hydraulic driving conditions of the square arc angle aquaculture tank can improve the efficiency of sewage discharge in different degrees. The results of this study can provide theoretical reference and optimization direction for improving the rapid sewage discharge of the square arc angle aquaculture tank.