Abstract: With the large-scale development of offshore wind power, the comprehensive utilization of marine multi-energy has attracted widespread attention. In the background of the dual-carbon strategy, it is of great significance to explore the feasibility of adding wave energy devices in the offshore wind farms. An asynchronous planning model and optimization method for the offshore wind and wave energy combined power generation considering the operation and maintenance requirements are proposed.Considering the electricity consumption demand of the offshore wind farms during shutdown and maintenance, the wave energy power generation devices are added to the existing offshore wind farms. Considering the constraints of the engineering requirements, such as the location of offshore wind turbines, operation and maintenance, and ship berthing and collision avoidance, the layouts of the wave energy power generation devices are optimized. The joint layout scheme of the offshore wind energy and wave energy devices is evaluated, and the optimization method is finally obtained considering the economy and feasibility comprehensively. The results of case study show that the adoption of the planning model and optimization method for the combined power generation can effectively improve the economic benefits of combined power generation and the convenience of operation and maintenance of wind turbine, while ensuring the reliability of the combined power generation.