▎ 摘　　要

NOVELTY - Polymer composite material comprises a polymer matrix and a composite with a 3-dimensional thermally conductive network chain structure, where the composite comprises graphene and carbon nanotubes, and the graphene and the carbon nanotubes form a 3-dimensional thermally conductive network chain structure. USE - The material is useful in heat energy utilization, heat exchange equipment, electronics industry and industrial heat dissipation applications. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing the polymer composite material involving adding graphene and carbon nanotubes to a solution (I) comprising a dispersant to obtain a solution (II), carrying out liquid phase shearing on the second solution to obtain a graphene and carbon nanotubes form a 3-dimensional thermally conductive network chain structure to obtain a solution (III) and microwave processing the solution (III) to obtain the product, where the composite and the polymer matrix are melt-mixed to obtain a polymer composite material.