The invention discloses a wave power generation device and a control method. The device comprises a bracket, a power generation device, a controller, a buoy, a GPS orientator arranged on the buoy, and a water device; and the water device includes a roller, a rotating shaft arranged in the roller, fixed rings slidingly connected with two ends of the rotating shaft, two cables connected with the two fixed rings, pressure sensors arranged at the lower parts of the two cables, airbags arranged in metal pipes at the lower ends of the cables and capable of vertically extending, igniters connected with the airbags, and main anchor nails and multiple side anchor nails arranged in metal pipes at the lower parts of the airbags. The device has the characteristics of wide application range, high energy conversion efficiency and excellent stability.