A side plate mounting structure, comprising: a side plate body; a locking portion connected to the side plate body, the locking portion being provided with a locking position when connected, in use, to a mounting base, and an unlocking position when separated from the mounting base; wherein the side plate body is provided with a through hole, and a part of the locking portion is connected to a hole wall of the through hole, the other part of the locking portion is stretched to the unlocking position along a first direction, or the other part of the locking portion is reset from the unlocking position to the locking position along a second direction opposite to the first direction; wherein the locking portion comprises: a connecting plate, a first end of the connecting plate being connected to the hole wall of the through hole, and a second end of the connecting plate extending toward a hole center of the through hole; and a locking beam, the locking beam being connected to the second end of the connecting plate, the locking beam being movable to the unlocking position along the first direction, or the locking beam being reset to the locking position along the second direction; characterized in that the locking portion comprises: a handle connected to the locking beam, wherein the handle is located on a side, away from the connecting plate along a hole center direction of the through hole, of the locking beam, and an outer surface of the handle is disposed at a distance from the hole wall of the through hole. a side plate body; a locking portion connected to the side plate body, the locking portion being provided with a locking position when connected, in use, to a mounting base, and an unlocking position when separated from the mounting base; wherein the side plate body is provided with a through hole, and a part of the locking portion is connected to a hole wall of the through hole, the other part of the locking portion is stretched to the unlocking position along a first direction, or the other part of the locking portion is reset from the unlocking position to the locking position along a second direction opposite to the first direction; wherein the locking portion comprises: a connecting plate, a first end of the connecting plate being connected to the hole wall of the through hole, and a second end of the connecting plate extending toward a hole center of the through hole; and a locking beam, the locking beam being connected to the second end of the connecting plate, the locking beam being movable to the unlocking position along the first direction, or the locking beam being reset to the locking position along the second direction; characterized in that the locking portion comprises: a handle connected to the locking beam, wherein the handle is located on a side, away from the connecting plate along a hole center direction of the through hole, of the locking beam, and an outer surface of the handle is disposed at a distance from the hole wall of the through hole. a connecting plate, a first end of the connecting plate being connected to the hole wall of the through hole, and a second end of the connecting plate extending toward a hole center of the through hole; and a locking beam, the locking beam being connected to the second end of the connecting plate, the locking beam being movable to the unlocking position along the first direction, or the locking beam being reset to the locking position along the second direction; characterized in that the locking portion comprises: a handle connected to the locking beam, wherein the handle is located on a side, away from the connecting plate along a hole center direction of the through hole, of the locking beam, and an outer surface of the handle is disposed at a distance from the hole wall of the through hole.