The invention discloses a method for pre-desiliconization of molten iron through a KR method and relates to a method for removing silicon in molten iron. The method comprises the step of adding a desiliconization agent to molten iron in a molten iron tank so as to remove silicon in the molten iron while mechanical stirring is carried out, specifically, the silicon content of the molten iron is 0.7-1.2 wt%. By means of the method, the silicon content of the molten iron in a furnace is stabilized, consumption of slag and steel and iron materials of a converter is reduced, and meanwhile, the purposes of reducing converter splashing and low-cost steelmaking are achieved.