The motion control,path planning algorithm design and simulation of the USV/UUV system need to consider the effect of the current,and the constant current dynamic model has been widely used. This model is derived through simplified hydrodynamic principle,but there is rare verifying trial to support its reliability and accuracy. This paper has designed a verification trial to solve this problem. During the trial,the ocean current data and UUV trial data on several headings have been recorded,the comparing hardware-in-the-loop simulations under the same ocean current have been done. The trial data and simulation data have been compared finally,and the conclusion on the accuracy of the constant current model have been presented.