A method for producing a thermoplastic resin composite material includes mixing a thermoplastic resin, pulp pieces, and a compatibilizer, wherein the pulp pieces are defibrated into cellulose fibers while being mixed with the thermoplastic resin and the compatibilizer; and kneading the cellulose fibers with the thermoplastic resin. For arbitrary 10 sections of the thermoplastic resin composite material, a standard deviation of a proportion of an area occupied by the cellulose fibers per predetermined area is 15% or less.