▎ 摘　　要

NOVELTY - Preparing flame-retardant polymethacrylimide foam composite material involves adding monomer acrylonitrile, methacrylic acid, modified monomer methyl styrene, crosslinking agent, foaming agent, nucleating agent, initiator in the container, stirring uniformly, orderly adding nano silicon dioxide, graphene oxide, sodium montmorillonite, stirring until the nano particles are uniformly dispersed to obtain the reaction solution A, putting the reaction solution A into the constant temperature water bath, performing the reaction of the monomer, obtaining the reaction product B, injecting the reaction product B into the forming mould, then putting into the strong circulating water bath tank to react, synthesizing N-phenylmaleimide copolymer, dismounting the mould, putting the PMI copolymer into the oven, 80degrees Celsius preheating for 3h, then raising the temperature to 160degrees Celsius foaming 10h, at last 140degrees Celsius heat treatment 8h to obtain the flame-retardant polymethacrylimide foam composite material. USE - Method for preparing flame-retardant polymethacrylimide foam composite material. ADVANTAGE - The method enables to prepare flame-retardant polymethacrylimide foam composite material that prevents the graphene oxide and nano montmorillonite settlement, avoids the water bath polymerization process to obtain the uniform performance of PMI foam.