The invention discloses a high-strength wear-resisting cast steel liner plate and a preparation method thereof, and belongs to the technical field of casting. The preparation method comprises the following steps: adopting electric-furnace smelting, using 40 to 45 mass percent of a high-manganese steel waste material, 43 to 48 mass percent of Q 235 waste steel, 8.5 to 9.2 mass percent of carbon ferrochrome, 2.0 to 2.5 mass percent of ferrovanadium and 1.0 to 1.5 mass percent of Si-Ca-Ba-Al alloy as accessories, adding Cu-Mg alloy particles, (Ti, W) C powder and cast iron chippings in a steel ladle after smelting cast steel, and carrying out thermal treatment on a liner plate, thus obtaining (Ti, W) C particles which are uniformly distributed on a matrix structure. On the premise that the high-strength wear-resisting cast steel liner plate has high strength, the high-strength wear-resisting cast steel liner plate also has good wear resistance and good using effect.