The invention discloses a closed-cycle cooling water energy-saving driving system and method. The closed-cycle cooling water energy-saving driving system comprises a closed-type water tank and a closed-cycle cooling water loop communicated with the closed-type water tank. The closed-cycle cooling water loop comprises a water supply main pipe communicated with the closed-type water tank, a closed-type cooling water pump assembly, closed-type water heat exchangers, a plurality of parallel cooling device pipelines and a water return main pipe, wherein the closed-type cooling water pump assembly, the closed-type water heat exchanger and the cooling device pipelines are sequentially connected on the water supply main, and the water return main is communicated with the cooling device pipelines and the closed-type cooling water pump assembly. The closed-type cooling water pump assembly comprises closed-cycle cooling water pumps arranged on the water supply main pipe, and a double-speed motor driving the closed-cycle cooling water pumps. The inlets of the closed-cycle cooling water pumps are communicated with the water return main pipe, and the outlets of the closed-cycle cooling water pumps are communicated with the closed-type water heat exchangers. By means of the technical scheme proposed by the invention, the pump blocking phenomenon does not occur, energy loss is not caused, and safe and stable operation of a cooling water system can be guaranteed.