Backpack

The utility model provides a knapsack which comprises a knapsack body, an outer side bag and a middle layer, the outer side bag is arranged on the outer side of the bag body, and when the outer side bag expands towards the outside of the bag body, an outer side containing space is formed; the middle layer is formed by expanding the side wall of the bag body towards the interior of the bag body, and when the middle layer is expanded towards the interior of the bag body, a middle layer containing space is formed; the outer side bag and the middle layer are located on the same side of the bag body, and the outer side containing space is communicated with the middle layer containing space. The side bag containing space of the knapsack can be enlarged, the article containing requirement of a user is met, and user experience is improved. 本实用新型提供了一种背包，包括包体，还包括：外侧袋、中间层；所述外侧袋设于所述包体外侧，当所述外侧袋向所述包体的外部扩展时，形成外侧容置空间；所述中间层由所述包体侧壁向所述包体的内部扩展而成，当所述中间层向所述包体的内部扩展时，形成中层容置空间；所述外侧袋与所述中间层位于包体同一侧，且所述外侧容置空间与所述中层容置空间相连通。本实用新型能够扩大背包的侧袋容置