A solid jointing disc brake disc structure comprises an outer ring piece, a first inner ring piece arranged on one side of the outer ring piece and a second inner ring piece arranged on the other side of the outer ring piece, wherein a combined jointing hole is formed in the surface of the outer ring piece, a plurality of clamp protruding parts are arranged on an extension ring of the outer ring piece and the combined jointing hole, the outer edge of the first inner ring piece is connected with the combined jointing hole in a combined jointing mode, a plurality of first clamping grooves are formed corresponding to the a plurality of clamp protruding parts on the first inner ring piece, the outer edge of the second inner ring piece is connected with the combined jointing hole in a combined jointing mode, the outer ring piece is arranged between the first inner ring piece and the second inner ring piece, and a plurality of second clamping grooves are formed corresponding to the plurality of clamp protruding parts on the second inner ring piece. According to the solid jointing disc brake disc structure, due to the fact that the contact area between the first inner ring piece and the outer ring piece and the contact area between the second inner ring piece and the outer ring piece are increased, the effect of solid jointing is achieved, the service life of a braking system is prolonged, and brake effect is improved.