▎ 摘　　要

NOVELTY - Preparing a high-absorbing polymer-based electromagnetic shielding composite material comprises e.g. (i) dissolving the polymer in the solvent, adding magnetic particles, ultrasonically dispersing evenly, pouring the resulting mixture into a poor solvent, stirring for 1-3 hours to form a precipitate, filtering it with suction, and drying it to obtain a magnetic particle/polymer composite material; (ii) adding the magnetic particle/polymer composite material and conductive filler obtained into a crusher and crushing to obtain a composite powder; and (iii) paving the composite powder in multiple layers according to the gradient change of the conductive filler content in each layer and carrying out thermocompression molding. USE - The method is useful for preparing high-absorbing polymer-based electromagnetic shielding composite material is useful in portable micro-electronic device and electronic appliance shell industry. ADVANTAGE - The method: prepares high absorption polymer-based electromagnetic shielding composite material with excellent electromagnetic shielding performance and very low reflection coefficient; can adjust the content of the conductive filler and the magnetic particles, crushing time and hot press parameter thus flexibly controls the wave absorbing performance and electromagnetic shielding efficacy which can satisfy precise electronic component sensitive to electromagnetic wave secondary reflection or electronic appliance shell industry; and has smart design and simple step. DETAILED DESCRIPTION - Preparing a high-absorbing polymer-based electromagnetic shielding composite material comprises (i) dissolving the polymer in the solvent, adding magnetic particles, ultrasonically dispersing evenly, pouring the resulting mixture into a poor solvent, stirring for 1-3 hours to form a precipitate, filtering it with suction, and drying it to obtain a magnetic particle/polymer composite material, the polymer comprises polyamide-6, total polyurethane, polystyrene or polyvinyl chloride, the solvent comprises dimethyl formamide, toluene, tetrahydrofuran, acetone or formic acid and the 1-40 wt.% magnetic particles comprising at least one of nano ferric oxide, carbonyl iron, ultrafine metal iron powder, and/or nickel powder and the poor solvent comprising water, methanol or ethanol; (ii) adding the magnetic particle/polymer composite material and conductive filler obtained into a crusher and crushing to obtain a composite powder and the 1-20 wt.% conductive filler comprising at least one of multilayer graphene, multi-walled carbon nanotubes, and/or nano-conductive carbon black; and (iii) paving the composite powder in multiple layers according to the gradient change of the conductive filler content in each layer and carrying out thermocompression molding. An INDEPENDENT CLAIM is also included for high-absorbing polymer-based electromagnetic shielding composite material, prepared as mentioned above.