Provided are an apparatus and method for synthesizing a conductive composite with enhanced electrical conductivity. The apparatus includes: an injection-molding machine which injection-molds pellets created by mixing carbon nanotubes (CNTs) with polymers; and an electric field generator which applies an electric field to the pellets that are melted while the melted pellets are injection-molded and thus rearranges the CNTs included in a composite into which the melted pellets are injection-molded.