The invention discloses a finalizing method of a sprinkling temperature-lowering finalizing device for electric power cable external insulation layer processing. An electric power cable insulation layer after completion of processing enters a temperature-lowering sprinkling water box, a circulating water hot water pump conveys 40 DEG C-50 DEG C hot water through a sprinkling water hot water pipe to continuously sprinkle the hot water to all sprinkling cloth curtains via sprinkling heads, so as to make the sprinkling cloth curtains fit on the upper face of the soft electric power cable insulation layer, the sprinkling cloth curtains are used for temperature lowering and cooling of the insulation layer, temperature lowering is performed until the surface of the insulation layer is finalized,and the electric power cable insulation layer with the surface finalized enters a next processing procedure through a wire-passing soft gasket in a wire outlet. The sprinkling temperature-lowering finalizing device is provided with the sprinkling heads and the cloth curtains; when the soft electric power cable insulation layer with higher temperature passes through, the surface layer of the softinsulation layer is finalized by the sprinkling cloth curtains, and the surface layer of the insulation layer is guaranteed to have a certain toughness and strength, the design is reasonable, unqualified products are reduced, the operation is convenient, and the quality of the products can be improved.