The invention relates to a method for producing high-quality plastic die steel forgings by forging of continuous casting slabs, and belongs to the technical field of steelmaking of medium-thickness slabs. The method is characterized in that the continuous casting slab is forged to produce the forging of which the plastic die steel surface hardness difference is smaller than +/-2HRC; the heating type adopts sectional heating; in the forging technology, before drawing put, the upper surface and lower surface are chilled, and the core part still maintains high temperature, so that the deformationof the core part is forcibly increased by a hard casing at the surface, the deformation degree of the core part is increased by 10% to 50%, and the surface hardness difference of the forging is 0+/-2HRC. The method has the advantages that the rate of finished product is improved, the ratio of forging waste of a user is greatly reduced to be 1% or less, the total cost of the forging is reduced, and the market competitiveness of the forging is improved.