Offshore wind farm is the latest direction of the wind power technology，with the further development of offshore wind farms technology，it is inevitable that future trend of offshore wind farms from offshore to deep sea. With increasing of sea- water depth，the cost of wind farm construction increased. The technology of floating wind turbine is an effective way to solve this problem. This paper systematically describes that early history，current situation and latest research of deep- sea floating wind turbine in the foreign academics，focuses on its theoretical analysis，simulation and hydrodynamic experimental，further refers to the shortcomings of that studies，accordingly propose some new research directions and ideas.