The invention relates to a wind energy and wave energy combined generating system in the technical field of ocean energy source utilization, comprising a floating foundation, a wind power generator set and a plurality of wave energy generating devices, wherein the wave energy generating devices are arranged in the circumferential direction around the floating foundation and are fixedly connected with the floating foundation; the wind power generator set is installed on the floating foundation, and the wind power generator set and the wave energy generating devices are respectively connected with the same transmission line to transmit electric energy; and the floating foundation is fixed on the sea. The wind energy and wave energy combined generating system avoids repeated construction to achieve the purpose of reducing the construction cost, increases the area of the water plane of the floating foundation to be beneficial to improving the stability of the whole set of system, improves the utilization rate of waves, saves space and enhances the protection.