Model experiment criterion is the core of flume model experiments, which will directly influenced the accuracy of the final results. In this paper, we made a research on a widely used circular HDPE sea cage system in China. We designed and made the cage model under the Tauti Criterion and Dickson Criterion (the large scale is 10, and the small scale is 2). The hydrodynamic model experiments are conducted in a circulation water channel, so as to compare the different results under the two criteria. The studies showed that drag of the whole cage and cage net decreases as the velocity increases, and there is a power function relationship between them; the whole cage’s drag coefficient decreases as the Reynolds number(Re) increases, which can be expressed as C=17.587 Re-0.354(R2 = 0.941); the relationship between net’s drag coefficient and Reynolds number is same to the whole cage’s, C=30.526 Re-0.424 (R2 = 0.902); When the actual velocity is 30cm/s-130cm/s, the experiment results under Tauti Criterion are always about 5% smaller than that under Dickson Criterion. The results showed both the two criteria can be exactly used in the cage model experiment. This paper provided theoretical basis and basic parameters to circular cage’s hydrodynamic calculation.