Abstract: A method for manufacturing an integral multilayer foam board with concave/convex surface and multiple colors. The method includes steps of placing a multilayer foam body having multiple colors into a heating means to be heated and softened at a temperature within 130.degree. C. to 170.degree. C., placing the multilayer foam body onto a mold and pressed thereinto to be molded with multiple convex portions defined by concave frame lines, partially planing the convex portion of the foam body, and placing the planed foam body into the heating means to be re-heated at a temperature within 100.degree. C. to 140.degree. C., making the convex portions form concave portions and the frame lines become convex.