A wave power generation system comprising: a wave receiving member provided near a virtual reflection surface configured to reflect a coming incident wave, the wave receiving member being configured to swing toward a first side in a swing direction by receiving force of the incident wave and swing toward a second side in the swing direction by receiving force of a reflected wave reflected by the virtual reflection surface; a ram cylinder hydraulic pump device configured to convert a swinging motion of the wave receiving member into a linear motion to discharge an operating liquid to a main passage; and an accumulator device configured to accumulate, under pressure, the operating liquid discharged from the hydraulic pump device and discharge the accumulated operating liquid when pressure in the main passage decreases; a change value sensor configured to detect a change value that changes in accordance with a swing amount of the wave receiving member; a hydraulic motor configured to be supplied with the operating liquid flowing through the main passage and drive an output shaft of the hydraulic motor based on an output value corresponding to pressure and flow rate of the supplied operating liquid; a power generator configured to generate electric power corresponding to the output value given to the output shaft of the hydraulic motor and change a torque command used during power generation; and a controller configured to set the torque command, wherein: based on a differential value of the value detected by the change value sensor, the controller determines whether the wave receiving member is swinging toward the first side or second side in the swing direction; and when the controller determines that the wave receiving member is swinging toward the second side in the swing direction, the controller changes the torque command from the torque command set when the controller determines that the wave receiving member is swinging toward the first side in the swing direction. a wave receiving member provided near a virtual reflection surface configured to reflect a coming incident wave, the wave receiving member being configured to swing toward a first side in a swing direction by receiving force of the incident wave and swing toward a second side in the swing direction by receiving force of a reflected wave reflected by the virtual reflection surface; a ram cylinder hydraulic pump device configured to convert a swinging motion of the wave receiving member into a linear motion to discharge an operating liquid to a main passage; and an accumulator device configured to accumulate, under pressure, the operating liquid discharged from the hydraulic pump device and discharge the accumulated operating liquid when pressure in the main passage decreases; a change value sensor configured to detect a change value that changes in accordance with a swing amount of the wave receiving member; a hydraulic motor configured to be supplied with the operating liquid flowing through the main passage and drive an output shaft of the hydraulic motor based on an output value corresponding to pressure and flow rate of the supplied operating liquid; a power generator configured to generate electric power corresponding to the output value given to the output shaft of the hydraulic motor and change a torque command used during power generation; and a controller configured to set the torque command, wherein: based on a differential value of the value detected by the change value sensor, the controller determines whether the wave receiving member is swinging toward the first side or second side in the swing direction; and when the controller determines that the wave receiving member is swinging toward the second side in the swing direction, the controller changes the torque command from the torque command set when the controller determines that the wave receiving member is swinging toward the first side in the swing direction. based on a differential value of the value detected by the change value sensor, the controller determines whether the wave receiving member is swinging toward the first side or second side in the swing direction; and when the controller determines that the wave receiving member is swinging toward the second side in the swing direction, the controller changes the torque command from the torque command set when the controller determines that the wave receiving member is swinging toward the first side in the swing direction.