Rotomolding-grade polyethylene filled modified composite material and preparation method thereof

The invention provides a rotomolding-grade polyethylene filled modified composite material and a preparation method thereof. The rotomolding-grade polyethylene filled modified composite material comprises, by weight, 25 to 90 parts of LLDPE1, 0 to 40 parts of LLDPE2, 10 to 50 parts of an inorganic filling material, 1 to 6 parts of a compatibilizing agent, 0.5 to 10 parts of a toughening agent, 0.1to 1 part of an antioxidant and 0.2 to 0.6 part of a lubricant, wherein the LLDPE1 and the LLDPE2 are two LLDPE materials with different performances; the inorganic filling material contains glass beads; and the compatibilizing agent is PE grafted maleic anhydride. The preparation method comprises the following steps: with linear low-density polyethylene resin as a matrix, filling the linear low-density polyethylene resin with the inorganic filling material, adding POE-g-GMA, POE-g-MAH and the like, and carrying out blending, granulation and grinding so as to prepare a rotomolding material. According to the invention