The invention discloses a method of taking polyaniline as an electroconductive agent to prepare a multi-phase composite electroconductive material. The method includes the following steps: (1), adding aniline monomers into ethylene-vinyl acetate copolymer powder to obtain swollen ethylene-vinyl acetate copolymer powder; (2), obtaining ethylene-vinyl acetate copolymer/polyaniline composite electroconductive powder; (3), obtaining ethylene-vinyl acetate copolymer/polyaniline/polylactic acid composite granules; (4) obtaining the multi-phase composite electroconductive material, wherein granularity of the ethylene-vinyl acetate copolymer powder in the step (1) is 40-120 meshes. By the method, the composite material high in electric conductivity can be obtained under the condition of low content of polyaniline and has high processing performance, and influence that other performances of the composite material are lowered due to increasing of content of polyaniline is reduced effectively.