A rotating shaft mechanism, comprising a main bracket and at least two rotating assemblies, wherein each rotating assembly can rotate relative to the main bracket, to switch between a folding state and an unfolding state, and a limiting structure configured to limit a maximum stroke of rotation performed by the rotating assembly relative to the main bracket is further disposed between the main bracket and the rotating assembly; a coordinating structure formed by the main bracket and any rotating assembly, a first rotation center and a second rotation center are formed on the main bracket, wherein each rotating assembly comprises a rotating member, a middle frame, and a sliding member, a third rotation center is formed on the middle frame, and axes of the first rotation center, the second rotation center, and the third rotation axis are parallel to each other; the rotating member comprises a first connecting portion, a second connecting portion, and a main body portion connected between the first connecting portion and the second connecting portion, wherein the first connecting portion can be rotatably connected to the main bracket about the first rotation center, and the second connecting portion can be rotatably connected to the middle frame about the third rotation center; one end of the sliding member can be rotatably connected to the main bracket about the second rotation center, the other end of the sliding member slidably coordinates with the middle frame, so that the middle frame is away from or close to the second rotation center along an extension direction of the sliding member; and when the rotating assembly is in the unfolded state relative to the main bracket, a bearing surface of the main bracket and a bearing surface of the middle frame are located on a same plane, characterised in that the first connecting portion and the second connecting portion are both arc structures, and a concave surface of the first connecting portion and a concave surface of the second connecting portion both face a side on which the bearing surface of the middle frame is located; a first arc sliding slot is formed on the main bracket, and the first connecting portion extends into the first arc sliding slot to slidably coordinate with the first arc sliding slot; a second arc sliding slot is formed on the middle frame, and the second connecting portion extends into the second arc sliding slot to slidably coordinate with the second arc sliding slot; and in a process in which the middle frame rotates relative to the main bracket, the first connecting portion does not protrude from the bearing surface of the main bracket, and the second connecting portion does not protrude from the bearing surface of the middle frame. a coordinating structure formed by the main bracket and any rotating assembly, a first rotation center and a second rotation center are formed on the main bracket, wherein each rotating assembly comprises a rotating member, a middle frame, and a sliding member, a third rotation center is formed on the middle frame, and axes of the first rotation center, the second rotation center, and the third rotation axis are parallel to each other; the rotating member comprises a first connecting portion, a second connecting portion, and a main body portion connected between the first connecting portion and the second connecting portion, wherein the first connecting portion can be rotatably connected to the main bracket about the first rotation center, and the second connecting portion can be rotatably connected to the middle frame about the third rotation center; one end of the sliding member can be rotatably connected to the main bracket about the second rotation center, the other end of the sliding member slidably coordinates with the middle frame, so that the middle frame is away from or close to the second rotation center along an extension direction of the sliding member; and when the rotating assembly is in the unfolded state relative to the main bracket, a bearing surface of the main bracket and a bearing surface of the middle frame are located on a same plane, characterised in that the first connecting portion and the second connecting portion are both arc structures, and a concave surface of the first connecting portion and a concave surface of the second connecting portion both face a side on which the bearing surface of the middle frame is located; a first arc sliding slot is formed on the main bracket, and the first connecting portion extends into the first arc sliding slot to slidably coordinate with the first arc sliding slot; a second arc sliding slot is formed on the middle frame, and the second connecting portion extends into the second arc sliding slot to slidably coordinate with the second arc sliding slot; and in a process in which the middle frame rotates relative to the main bracket, the first connecting portion does not protrude from the bearing surface of the main bracket, and the second connecting portion does not protrude from the bearing surface of the middle frame.