Energy shortage is becoming more and more severe worldwide, so does the environment pollution. Conventional fossil fuels is not sustainable and the storage capacity is decreasing faster than ever before. The exploitation and utilization of renewable energy has become an effective measure to deal with the present energy shortage situation. In order to improve the power production capacity, power output quality, income investment ratio, the comprehensive marine energy has become a new trend of marine renewable energy. At present, the research of offshore renewable energy power generation devices mainly focuses on tidal energy, wave energy and offshore wind energy. For the scale deployment of offshore renewable energy power generation device, safe and reliable platform is essential. The development of safe and reliable, cost effective platform is the basis of the whole industry. Furthermore, single renewable energy power generation device limits the development of the industry due to the poor stability and low income investment ratio. To solve the above problem, a new type of Wind-Flow combined power generation device was designed, including turbine and the wind turbine design. Then, an initial mooring system was designed according to the property of the device. The feasibility of mooring system design is verified by the time-domain calculation of the irregular wave by using AQWA DRIFT. The platform was verified according to CCS Classification of offshore mobile platforms. The static hydrostatic curve of the power plant was calculated by Maxsurf software, the maximum static heeling angle is equal to 30.9°. The stability of the platform was verified according to the IMO-A.749 (18) -Ch3 standard. The maximum offset surge value of the power generation device is below 20m in the target sea area. The maximum tension of the mooring line in the complete survival condition is 1198kN, the safety factor is 3.08. The results can provide reference for future research in this area.