The invention discloses an assembled concrete full-closed noise barrier. The assembled concrete full-closed noise barrier comprises noise barrier bases, a plurality of cross beams and cover plates, wherein the cross beams are arranged in a bridge direction at intervals and shaped like a closed circle; the cover plates are laid between the surfaces of the adjacent cross beams and the sections of the cover plates are consistent with the sections of the cross beams in the bridge direction; each cross beam comprises a top cross beam and two side cross beams; one ends of the side cross beams are fixedly connected with the noise barrier, the other ends of the side cross beams are fixedly connected with the top cross beams, and the connected parts of the side cross beams and the top cross beams are concave-convex tooth mouth engaged structures; and the section of each cross beam in a transverse bridge direction is elliptic or circular, and the maximum width of the section of each cross beam in the transverse bridge direction is larger than the width of a bridge deck. Compared with the traditional steel cross beam, the assembled concrete full-closed noise barrier has the advantages that the assembled concrete full-closed noise barrier does not need to maintain and the durability of the assembled concrete full-closed noise barrier is good; the steel usage is reduced and the economic efficiency of the assembled concrete full-closed noise barrier is enhanced; the sound insulation effect is good, the durability is good, the manufacturing cost of the assembled concrete full-closed noise barrier is low and the fireproof performance is greatly enhanced; and through adoption of a convex integral curve form, the aerodynamic performance of the assembled concrete full-closed noise barrier is better than that of the traditional vertical noise barrier.