The invention discloses an expansive type halogen-free flame-retardant ethylene propylene diene monomer material. The material is prepared and processed from the following raw materials in parts by weight: 50-70 parts of ethylene propylene diene monomers, 30-50 parts of a surface-modified expansive type halogen-free flame retardant, 1-5 parts of a smoke suppressant, 1-3 parts of a processing aid and 2-5 parts of a vulcanizing aid, wherein the surface-modified expansive type halogen-free flame retardant is prepared from polyphenylphosphonate piperazine, phenyl phosphinate, melamine cyanurate or melamine polyphosphate through compounding. After the compound halogen-free flame retardant is subjected to wet process modification by virtue of a polysiloxane compounded titanate surface modifying agent, the water tolerance and consistency are obviously improved, the compound material has excellent flame retardance, water tolerance and physical and electric properties, the oxygen index reaches 43% or above, and the compound material reaches (1.6mm) V-0 level, can be widely applied to the fields of new energy automobile parts, electric wires and cables, electronic devices and equipment and the like and has good application prospects.