The paper introduced the working principle of a new wave energy generating device of oscillating blade type on ship.Based on the linear wave theory, it studied the hydrodynamic performance of the device and derived the wave energy formula of blades. By using Gambit and Fluent software, the paper simulated torque and axial force under variable velocity, which could lay a foundation for the analysis of wave energy efficiency and the ability of resisting wind and wave.The result shows that the average wave energy acquisition rate of the device is 4.37 percent. The application of the device to ship is good,which can provide the reference basis for the development and utilization of wave energy technology to ship.