The invention relates to a water-tree-retardant semiconductive shielding material and a preparation method thereof. The water-tree-retardant semiconductive shielding material is prepared from the following raw materials in parts by weight: 40 to 100 parts of ethylene-vinyl acetate copolymers, 0.1 to 5 parts of water tree inhibitor, 5 to 20 parts of ethylene-butyl acrylate copolymer, 40 to 80 parts of conductive carbon black, 0.1 to 1.5 parts of antioxidant, 0.5 to 10 parts of lubricant, 1 to 10 parts of dispersing agent, and 0.5 to 2.5 parts of cross-linking agent. By adopting the raw material formula of the components such as the ethylene-vinyl acetate copolymer, the ethylene-butyl acrylate copolymer and the water tree inhibitor, the polarity and a melt index of the semiconductive shielding material can be adjusted, and a water tree retardant effect can be achieved.