Abstract: To study the purification effect and the mechanism of ozone on suspended particulates in water, discuss its application and process integration in aquaculture water treatment, the authors built several smallscale test systems, added different amounts of ozone into aquaculture water, analyzed the effect on TSS and turbidity, and conducted the grading analysis of particle size of suspended particulates. The control group did not add ozone, and the ozone adding amount of the 3 test groups was 30.1, 60.2, 90.3 mg, respectively, the treated water volume were all 4 L. The results showed that: (1) adding ozone could remarkably reduce the turbidity of aquaculture water; the turbidity of the 3 test groups was reduced by 12.47%, 25.31% and 30.20% respectively when the turbidity of initial water was (5.22 ± 0.55) NTU; (2) adding ozone was helpful for coagulation of suspended particulates in water body; the particle size of the suspension particulates in control group was mostly distributed in 48-68 μm; however, the rate of the suspended particulates whose particle size was above the 64 μm was 99.22% in test group water with the ozone adding amount of 90.3 mg, which contributed to subsequent physical filtration. The study suggests that the effect of ozone purification on suspended particulates is achieved by changing particle size distribution by the way of oxidizing organic compounds to produce complex precipitates and colloidal flocs, which provides theoretical support for the application of ozone in circulating water system.