The invention belongs to the technical field of composite materials, and particularly relates to a metal-based polymer material preparation method. The method comprises the following steps of adding epoxy resin into a reaction kettle, heating and uniformly dispersing, adding 5-10 parts of modified epoxy resin, adding an epoxy diluent and a dispersing agent, adding an anti-settling aid, adding a polymerization aid, adding a defoaming agent, mixing Ti, iron oxide powder, electrolytic iron powder, reduced iron powder, carbon black, Cr, Mn, Mg, Zn, Wc, Al and ceramic micro powder to form metal mixed powder, and adding the metal mixed powder into a resin mixed solution, stirring, and defoaming. The preparation method of the composite material comprises the following steps of uniformly stirringthe curing agent and the high polymer material, controlling the temperature to be 20-35 DEG C for preliminary curing, and curing after the temperature is 80-160 DEG C to obtain the finished product. And the mold is made of a polymer composite material. And the prepared mold is high in strength and hardness, small in contractibility and good in sedimentation resistance.