Wave power generation device capable of converting potential energy from water level difference into electric energy

Disclosed is a wave power generation device, which comprises a cavity as a waterproof structure. The cavity comprises a soft plate as a plate-type structure made of soft material, which may be in a wavy shape moving up and down along with the wave while floating on the water; an upper plate, which is located above the soft plate, wherein the peripheral edges of the soft plate and the upper plate are connected by a sealing structure so that a hollow space is formed between the soft plate, the upper plate and the sealing structure; at least one elastic mechanism located in the hollow space having one end connected to the soft plate and the other end connected to the upper plate, wherein the end of the elastic mechanism connected to the soft plate is connected with a shaft that is extended upwardly through the upper plate from the interior of the corresponding elastic mechanism; and, the end of the shaft penetrated through the upper plate is connected with a converting device for converting the linear motion of