A suitcase, comprising: a main body, comprising a containing groove; a removable compartment, movably located in the containing groove, wherein the removable compartment comprises: a base layer; a covering layer, covering the base layer; at least one hole, located in the base layer; an inner opening unit, movably connected to the covering layer, wherein the inner opening unit is used for allowing the covering layer to be opened or closed, and the base layer is exposed to the outside when the covering layer is opened; at least one first main fastening unit, located in the containing groove; at least one second main fastening unit, located in the containing groove; and a plurality of fastening rings, connected to the base layer, and a plurality of positions of the plurality of fastening rings respectively correspond to the at least one first main fastening unit and the at least one second main fastening unit; wherein the at least one first main fastening unit comprises: - a fastening unit main body; - a fastening slot, the fastening slot being located on the fastening unit main body; - a fastening bar, the fastening bar being located in the fastening slot; - an operating unit, connected to the fastening bar and passing through the at least one hole; - a through hole, the through hole links to the fastening slot, and the fastening bar passes through the through hole. a main body, comprising a containing groove; a removable compartment, movably located in the containing groove, wherein the removable compartment comprises: a base layer; a covering layer, covering the base layer; at least one hole, located in the base layer; an inner opening unit, movably connected to the covering layer, wherein the inner opening unit is used for allowing the covering layer to be opened or closed, and the base layer is exposed to the outside when the covering layer is opened; at least one first main fastening unit, located in the containing groove; at least one second main fastening unit, located in the containing groove; and a plurality of fastening rings, connected to the base layer, and a plurality of positions of the plurality of fastening rings respectively correspond to the at least one first main fastening unit and the at least one second main fastening unit; wherein the at least one first main fastening unit comprises: - a fastening unit main body; - a fastening slot, the fastening slot being located on the fastening unit main body; - a fastening bar, the fastening bar being located in the fastening slot; - an operating unit, connected to the fastening bar and passing through the at least one hole; - a through hole, the through hole links to the fastening slot, and the fastening bar passes through the through hole. a base layer; a covering layer, covering the base layer; at least one hole, located in the base layer; an inner opening unit, movably connected to the covering layer, wherein the inner opening unit is used for allowing the covering layer to be opened or closed, and the base layer is exposed to the outside when the covering layer is opened; at least one first main fastening unit, located in the containing groove; at least one second main fastening unit, located in the containing groove; and a plurality of fastening rings, connected to the base layer, and a plurality of positions of the plurality of fastening rings respectively correspond to the at least one first main fastening unit and the at least one second main fastening unit; wherein the at least one first main fastening unit comprises: - a fastening unit main body; - a fastening slot, the fastening slot being located on the fastening unit main body; - a fastening bar, the fastening bar being located in the fastening slot; - an operating unit, connected to the fastening bar and passing through the at least one hole; - a through hole, the through hole links to the fastening slot, and the fastening bar passes through the through hole. - a fastening unit main body; - a fastening slot, the fastening slot being located on the fastening unit main body; - a fastening bar, the fastening bar being located in the fastening slot; - an operating unit, connected to the fastening bar and passing through the at least one hole; - a through hole, the through hole links to the fastening slot, and the fastening bar passes through the through hole.