The utility model discloses a tapered sleeve for reserved holes, which is formed through carrying out casting on plastics or PVC (polyvinyl chloride) materials. The two ends of the tapered sleeve are both in the shape of an open-mouthed circular truncated cone, an upper open mouth of the circular truncated cone is large, a lower open mouth of the circular truncated cone is small, and the top end of the outer side of the upper open mouth is provided with a reinforcing raised edge; and the sleeve wall at the lower part of the reinforcing raised edge is provided with at least two sets of dual-purpose holes in pairs, and two dual-purpose holes in a set are symmetrically arranged on the sleeve wall 4. The tapered sleeve is applied to the pouring of reserved holes of cement roof plates, and in the process of mold withdrawing by using the dual-purpose holes, because the outer wall is smooth and the lower mouth is small, the tapered sleeve is uneasy to have contact friction with the inner walls of holes, therefore, the upward lifting is facilitated, the edges of the reserved holes are not damaged, and the appearance forming effect is good. The lower mouth of the tapered sleeve for reserved holes is small and the upper mouth is large; and the tapered sleeve can be three-dimensionally stacked in an up-and-down mode, thus the floor space is reduced. The tapered sleeve for reserved holes, disclosed by the utility model, is simple and practical in structure and low in production cost; because plastic materials are adopted, the resources are saved; and the tapered sleeve can be subjected to batch production and can not be lost.