To separate the effect of oblique flow on navigable ship model in dynamic water, a duplication test method used in still water ship pond was put forward.The duplication test of the ship model in still water ship pond was implemented by using manipulated process recorded in dynamic water, the navigation parameters of two tests were taked to superpose together in vector, and then the distance of deviating sailing line due to the influence of oblique flow was obtained. Through the navigation test of TGP, the practical deviation distance was found, and the result is considered to be basically rational.