Objectives In order to study the impact of the hydrodynamic performance of foil in the design of a wave glider,Methods on account of the characteristics of the oscillating foil when the wave glider is heaving, and based on the Dynamic Fluid Body Interaction(DFBI) module in STAR-CCM+ with the SST k-ω turbulence model, the passive oscillating process of foil when it is forced to heave is simulated. The effects of limit angles,wave heights and frequencies on the thrust coefficient of NACA 0012 flapping foil are investigated.Results We find that the passive rotation method can effectively simulate foil oscillating process, and its thrust coefficient is about 30% smaller than the coefficient obtained by the active rotation method. Moreover, the maximum limit angle of a wave glider of around 20° gives a better hydrodynamic performance. The numerical simulation result indicate that the thrust coefficient increases with the increase of wave height and wave frequency in a certain region.Conclusions This can provide a reference for propulsive performance and hydrodynamic performance under different states of the sea.