The invention discloses an EPM composite. The EPM composite is prepared by blending, by weight, 30%-94% of CA, 5%-60% of fortifier, 0-40% of enhancer, 0.1%-1% of CDM2 disproportionating factors, 0.1%-1% of coupling agent, 0.1%-1% of antioxygen, 0.1%-1% of antiager, 0.1%-1% of ultraviolet light absorber, 0.1%-1% of lubricant and 0.1%-1% of triethyl aluminum. The EPM composite has the advantages of being simple in formula, low in cost, fireproof, high in strength, good in tenacity, not prone to deformation and good in paint adhesive force. A preparation method of the EPM composite comprises the steps that the evenly mixed fortifier and coupling agent, and the evenly mixed CA, CDM2 disproportionating factors, antioxygen, antiager, ultraviolet light absorber, lubricant and triethyl aluminum are added to a double-screw extruder, the enhancer is added from the side face, extruding and pelleting are carried out, and the granulous EPM composite is obtained. The advantages of being simple in procedure and easy and convenient to operate are achieved.