For the scheme selection of offshore wind power grid connection, an economical comparison model based on the life cycle cost (LCC) is established. A comparative analysis of the pros and cons of HVAC and VSC-HVDC using an offshore wind farm with capacity of 250 MW and 70 km distance from the shore. The results show that, although initial investment of the HVAC is much higher, but in the operation cost the HVAC significantly less than the VSC-HVDC, so it’s a better choice using the HVAC in this project. Furthermore, considering the factors of economy and transmission capacity, the optimization scheme of offshore wind power grid connection based on LCC model is established, which can provide reference for the actual project in the future. This work is supported by National Natural Science Foundation of China (No. 51577115).