Abstract: Gas-liquid two-phase flow model was applied to simulate mixing process of ozone-water in jet aerator. A comprehensive parameter distribution was obtained, which revealed the mixing mechanism of jet aerator to mix ozone-water. These provided a method for optimizing structural parameters of jet aerator and performance forecast. Relationship between optimal length of throat pipe and area ratio was analyzed. The results showed that the bigger area ratio, the longer throat pipe length, and the optimal length of throat pipe should be 5.84～7.47d1 when area ratio was 2.25～6.25.