The present invention relates generally to the offshore renewable energy utilization technology. A novel floating wind-wave integrated power generation system is based on the braceless semi-submersible floating wind turbine concept and the oscillating water column (OWC) wave energy generator. The integrated system includes the offshore wind energy system and the oscillation water column wave energy system. The novel floating wind-wave integrated power generation system transfers the rise and fall movement of the water column into the air in and out movement which is converted into the electricity by the air turbine generator. This invention makes good use of pontoons at of the semi-floating platform and the mooring lines. Since the wave energy system will move with the wave movement, which will reduce the power generation efficiency. The pontoon can help to mitigate this movement. The mooring system can further prevent the movement of the wave energy device. This invention uses the braceless structure, which simplifies the construction process and reduce the fatigue issues for the braces. Compared with the traditional three columns semi-submersible wind turbine, this invention enlarges the water plane area. The moment of inertia for hydrostatic stability is enhanced, and the stability of the floating foundation is improved.