The wave glider powered by waves has a unique dual-body architecture and can perform long-duration operational tasks in the ocean. In this paper, to accurately predict its maneuverability, the horizontal plane 3-degree of freedom (DOF) dynamic models of the surface float and the submerged glider are established separately. The influence of ocean currents is considered, and the influence of the torsional moment of the umbilical cable is considered for the first time. The hydrodynamic coefficients of the submerged glider will vary with different rudder angles and angles of attack of incoming flow. The computational fluid dynamics (CFD) method is used to analyze and calculate added mass coefficients and damping coefficients corresponding to different rudder angles based on planar motion mechanism (PMM) test simulation and oblique navigation dynamic test simulation. The flow fields are analyzed under different working conditions. The structural parameters of the wave glider and the hydrodynamic coefficients obtained from the simulation are brought into the dynamic model. The rotary motion and the Z-shaped motion under different sea conditions and currents are numerically analyzed. The difference of the hysteresis of the surface float relative to the submerged glider in yaw motion are analyzed under different ocean currents and rudder angles. Sea trial and simulation results show that the established dynamic model and obtained hydrodynamic parameters can accurately basically predict the maneuvering performance of the wave glider.