The invention discloses a seawave generating device which is the improvement on the previous invention of trident swinging paddle seawave generating device (patent number is 2012102126753) of the inventor. Components such as a floater, an electrical machine buoyancy tank, a triangular cross beam, a fixed support and a locating sleeve ring are additionally arranged, the process is more advanced, the structure is firmer, and the finished product can be sold in a complete set. The trident swinging paddle is adopted for collecting up-down fluctuation energy of sea wave and advance-retreat impact energy of the sea wave at the same time, so that the efficiency is high, power is high, and benefit is great. If only the triangular cross beam and a transmission shaft are firm enough, the generating capacity of ten thousand kilowatts and even hundreds of thousands of kilowatts can be completely realized. The trident swinging paddle can be a milestone in the seawave generating technology in future.