The invention discloses a patterned-cover expansion die. The patterned-cover expansion die comprises an upper die and a lower die; the upper die comprises an upper die seat, a cylindrical core die seat and an arc-shaped polyurethane core die, wherein the upper die seat is provided with a circular through hole, the cylindrical core die seat can penetrate through the circular through hole in the upper die seat, and the arc-shaped polyurethane core die can be connected with the cylindrical core die seat; the lower die comprises a female die and a positioning die seat, wherein the female die is provided with an arc-shaped cavity, the positioning die seat is formed by a plurality of mutually-spliced slide-block pattern dies which are the same in size and structure, and the inner side wall of the arc-shaped cavity is a concave-convex-shaped pattern die wall which can form patterns on a patterned-cover parison; and the slide-block pattern dies are arranged on the top of the female die, and can move inwards or outwards on the female die, and the slide-block pattern dies can gradually be spliced to form the positioning die seat with a circular through hole through moving inwards. The patterned-cover expansion die has the advantages that the structure is sample, using is convenient, and the working efficiency is enhanced, so that sixty patterned covers can be produced in one hour.