To provide a bundling method of a steel belt and a sleeve which can firmly bundle the steel belt even if the width of the steel belt is narrower than that of the sleeve in the case that the steel belt is rolled up on the sleeve.

A hoop 15 is passed through a groove 24 with the sleeve 14 having the steel belt 11 rolled up thereon. Then, the hoop 15 approaches both steel belt's side faces 31 by inflecting the hoop 15 at respective boundaries between the steel belt's inner curved surface 30 positioned inside the laminating direction of the steel belt 11 and respective side faces 31 positioned at both the two opposite sides along the center axis direction. Then, at boundaries between the respective side faces 31 of the steel belt and the steel belt's outer curved surface 32 positioned at the outside of the laminating direction of the steel belt 11, the hoop 15 is inflected so that it may approach the steel belt's outer curved surface 32, and thereby the hoop 15 is wound around the steel belt 11 so that the hoop 15 may be brought to be formed into an approximately rectangular shape of a frame.