A middle frame assembly, characterized in that the middle frame assembly comprises: a middle frame, comprising a frame body having a first face and a second face opposite to the first face, wherein the frame body defines a plurality of first through holes penetrating the first face and the second face;the frame body comprises an inner wall connecting the first face and the second face, and the inner wall defines a through groove penetrating the first face and the second face; and a bearing plate, comprising: a bearing body having a third face, a fourth face opposite to the third face and an outer wall connecting the third face and the fourth face; and a plurality of first extending portions (44, 44a) protruding from the third face; wherein each of the plurality of first extending portions (44, 44a) is configured to pass through a corresponding first through hole and fitting with the frame body, such that the bearing body is connected to the frame body and that the first face and the third face abut against each other; wherein a plurality of protrusions are arranged on the outer wall of the bearing body, the plurality of protrusions are spaced apart from each other; the plurality of first extending portions (44, 44a) are arranged on the plurality of protrusions; a plurality of second through holes are defined in the plurality of protrusions; the middle frame further comprises a plurality of second extending portions protruding from the first face and configured to pass through a corresponding second through hole and have an interference fit with the bearing body; and the bearing body is arranged corresponding to the through groove, and a projection of the bearing body on a plane where the second face is located is in the through groove, a slot is defined between a projection of the inner wall of the frame body on the plane and a projection of the outer wall having the plurality of protrusions arranged thereon on the plane. a middle frame, comprising a frame body having a first face and a second face opposite to the first face, wherein the frame body defines a plurality of first through holes penetrating the first face and the second face;the frame body comprises an inner wall connecting the first face and the second face, and the inner wall defines a through groove penetrating the first face and the second face; and a bearing plate, comprising: a bearing body having a third face, a fourth face opposite to the third face and an outer wall connecting the third face and the fourth face; and a plurality of first extending portions (44, 44a) protruding from the third face; wherein each of the plurality of first extending portions (44, 44a) is configured to pass through a corresponding first through hole and fitting with the frame body, such that the bearing body is connected to the frame body and that the first face and the third face abut against each other; a bearing body having a third face, a fourth face opposite to the third face and an outer wall connecting the third face and the fourth face; and a plurality of first extending portions (44, 44a) protruding from the third face; wherein each of the plurality of first extending portions (44, 44a) is configured to pass through a corresponding first through hole and fitting with the frame body, such that the bearing body is connected to the frame body and that the first face and the third face abut against each other; wherein a plurality of protrusions are arranged on the outer wall of the bearing body, the plurality of protrusions are spaced apart from each other; the plurality of first extending portions (44, 44a) are arranged on the plurality of protrusions; a plurality of second through holes are defined in the plurality of protrusions; the middle frame further comprises a plurality of second extending portions protruding from the first face and configured to pass through a corresponding second through hole and have an interference fit with the bearing body; and the bearing body is arranged corresponding to the through groove, and a projection of the bearing body on a plane where the second face is located is in the through groove, a slot is defined between a projection of the inner wall of the frame body on the plane and a projection of the outer wall having the plurality of protrusions arranged thereon on the plane.