In order to investigate the influences of different fluid solid coupling method on hydrodynamic propeller and strength, firstly, the propeller model is established. The model was pretreated using oneway and twoway flow solid coupling (FSI) method in the Workbench platform, to a certain type of propeller in different velocity of open water, surface pressure distribution, stress equivalent calculation and comparative analysis and deformation, to get the open water performance curves, curves of different crosssection pressure distribution curves and stress and deformation changes with the blade radius. The results show that: in the low velocity coefficient, open water performance results of the twoway FSI calculation accuracy is higher than that of unidirectional FSI, with the speed coefficient increases, the gap of two methods of calculating value is getting smaller and smaller; the peak pressure of oneway FSI is higher than the twoway FSI, but the twoway FSI by pressure is more uniform in distribution; unidirectional flow FSI by the stress and deformation peak is higher than the twoway FSI, with the increase of inlet velocity coefficient, two kinds of FSI method to calculate the deviation is increased.