The invention discloses a using method of a double-layer staggered zipper. The double-layer staggered zipper comprises a zipper base and a zipper strip, wherein the zipper base comprises an upper zipper plate, an upper zipper closing column, a middle zipper plate, a lower zipper closing column and a lower zipper plate; the zipper strip comprises an upper zipper strip and a lower zipper strip; the upper zipper strip comprises a left upper zipper strip and a right upper zipper strip; the left upper zipper strip consists of a left upper zipper buckle and left upper zipper cloth; the right upper zipper strip consists of a right upper zipper buckle and right upper zipper cloth; the lower zipper strip comprises a left lower zipper strip and a right lower zipper strip; the left lower zipper strip consists of a left lower zipper buckle and left lower zipper cloth; the right lower zipper strip consists of a right lower zipper buckle and right lower zipper cloth; the left upper zipper buckle is provided with a left upper insertion-preventing component; the right upper zipper buckle is provided with a right upper insertion-preventing component; the left lower zipper buckle is provided with a left lower insertion-preventing component; the right lower zipper buckle is provided with a right lower insertion-preventing component. During using, the double-layer staggered zipper is mounted on a luggage case or a luggage bag, and the staggered double-layer zipper, the left upper insertion-preventing component and the right upper insertion-preventing component, or the staggered double-layer zipper, the left lower insertion-preventing component and the right lower insertion-preventing component are used for blocking gaps between the zipper strips, so that the difficulty for a lawbreaker to open the zipper through insertion by using a sharp device is enhanced.