Wave energy has not yet been commercialized due to its high cost and low efficiency. The combination of wave energy devices and breakwaters can greatly improve the utilization of breakwaters and also reduce the cost of wave power generation devices. In this paper, four oscillating buoy wave energy devices with different geometries are proposed, where a kind of dolphin buoy design method with excellent energy harvesting mechanism is formed. And the integrated method of wave energy device and floating breakwater is proposed and the integrated model is tested in the tank, and on the basis of that a one-year sea trial test of the prototype was carried out in the real sea area, and the power generation performances of the wave energy device under different sea conditions are analyzed. The sea trial results show that the average energy conversion efficiency of wave energy device can reach more than 18% when the significant wave height is from 0.5 m to 2 m and an average period is from 2 s to 6 s, and that can even reach 27.2% under the optimal sea state. The research and manufacturing process of sea trial prototype and the sea trial operation of the prototype show that the combination of oscillating buoy wave energy device and floating breakwater can reduce the construction cost of wave energy device and also improve reliability and energy conversion efficiency of that. The research results of this paper are of great significance for the further commercialization of wave energy devices.