The invention provides an adjustable positioning drum shoulder. The drum shoulder comprises a left drum shoulder body, a right drum shoulder body, a connecting key bar and fixing bolts. Positioning holes are formed in the left drum shoulder body and the right drum shoulder body. The left drum shoulder body and the right drum shoulder body can slide on the connecting key bar leftwards and rightwards by fixing the fixing bolts to the connecting key bar. The function of producing rubber tire surfaces of various specifications can be achieved through the same drum shoulder by adjusting the width of the positioning drum shoulder, so that the production cost of the drum shoulder is reduced, and the workload for replacing the drum shoulder and the daily maintenance cost are reduced; and meanwhile the equipment cost is reduced.