The invention belongs to the technical field of novel materials and in particular relates to a polyethylene modified material and a preparation method thereof. The polyethylene modified material comprises polyethylene resin, a waste polyethylene plastic, a mixture of solid alkane, zinc stearate, calcium stearate, vinyl bistearic amide and an antioxidant. The polyethylene resin and the waste polyethylene plastic are adopted as base materials, various aids are added, and the polyethylene modified material is prepared by using a preparation process researched in the invention. The modified material has excellent advantages of cold resistance, thermal resistance, chemical resistance, wearing resistance, lubrication performance, and the like, and so that has very good lubrication and compatibility functions in processing molding of a plastic or a color master batch. When the polyethylene modified material is used in processing molding of the plastic or the color master batch, the flowability of a material can be improved, the gloss, the lubrication performance and the processing performance of a product can be improved, the yield can be increased, and in addition, a higher filler concentration can be allowed.