The invention provides a strengthening method for a shell. The strengthening method comprises the following steps of offering a colored glaze shell, and carrying out salt mist strengthening treatment on the shell, wherein the initial temperature of the shell in salt mist strengthening treatment is 480-550 DEG C, a spray liquid is utilized for spraying the shell, and the spray liquid contains potassium nitrate, potassium silicate, kieselguhr and water. According to the strengthening method, the shell is prepared by colored glaze; and by adopting the salt mist strengthening method and utilizing substitutional diffusion of alkali metal ions, the surface chemical components of the shell are changed so as to form a compact outer surface, so that the extrusion stress of the shell surface is increased and the mechanical strength of the shell is improved. The invention also provides the shell prepared by the method.