According to the features of 660 MW ultra super-critical units and the manufacturing situation of domestic feedwater pump, the advantages, disadvantages and the problems of three schemes are analyzed for 100% or 2x50% capacity turbine-driven and 100% capacity main steam turbine driven feedwater pump. By analyzing the technical and economic factors of three schemes, it is found that the scheme of 100% capacity host-driven pump is optimal, providing references for similar units design.