Disclosed are a wave power generation system for generating power by means of a hydraulic circuit, and a method for controlling same. The wave power generation system comprises: a tension transmission member for transmitting motion energy which is generated by means of six-degrees-of-freedom motion of a movable object floating on the waves; a power conversion unit comprising a fluid pressure generation unit which is connected to the tension transmission member and is for generating a fluid pressure; and an equalizer connected to the tension transmission member and for maintaining the tension of the tension transmission member. In the power conversion unit, if tension is applied from the tension transmission member, the fluid pressure generation unit enables a fluid to flow in a first direction by means of the tension and, if tension is not applied from the tension transmission member, the fluid pressure generation unit enables a fluid to flow in a second direction by means of the equalizer.