A cover plate assembly, applied to a battery and comprising: a cover plate comprising a cover plate body and a carrier portion connected with each other, wherein the cover plate body has a first surface and a second surface opposite to each other, the cover plate body is disposed around an external periphery of the carrier portion, the carrier portion is recessed from the first surface, the carrier portion and the cover plate body cooperatively define a first recess, and the carrier portion defines a first through hole communicating with the first recess; and when the cover plate assembly is applied to the battery, the first surface is closer to an outside of the battery than the second surface; a pole disposed in the first recess, abutting against the carrier portion and configured to be electrically connected with a current collector of the battery, wherein the pole defines a second through hole; and an explosion-proof assembly comprising an explosion-proof valve and a protective sheet, wherein the explosion-proof valve and the protective sheet are disposed in the second through hole, the explosion-proof valve is spaced apart from the protective sheet, the explosion-proof valve is disposed closer to the second surface than the protective sheet, and the explosion-proof valve is configured to seal the second through hole; wherein the pole comprises an abutting portion and a pole body connected with each other, the abutting portion is disposed in the first recess and abuts against the carrier portion, the pole body exceeds the first surface, the second through hole penetrates through the abutting portion and the pole body, and the second through hole penetrates through a surface of the pole body away from the abutting portion; and wherein the second through hole comprises a first through sub-hole and a second through sub-hole that communicate with each other in a bent manner, the first through sub-hole penetrates through a surface of the abutting portion away from the pole body, the explosion-proof valve is disposed in the first through sub-hole, the second through sub-hole penetrates through a surface of the pole body connected with the abutting portion, and the protective sheet is disposed in the second through sub-hole. a cover plate comprising a cover plate body and a carrier portion connected with each other, wherein the cover plate body has a first surface and a second surface opposite to each other, the cover plate body is disposed around an external periphery of the carrier portion, the carrier portion is recessed from the first surface, the carrier portion and the cover plate body cooperatively define a first recess, and the carrier portion defines a first through hole communicating with the first recess; and when the cover plate assembly is applied to the battery, the first surface is closer to an outside of the battery than the second surface; a pole disposed in the first recess, abutting against the carrier portion and configured to be electrically connected with a current collector of the battery, wherein the pole defines a second through hole; and an explosion-proof assembly comprising an explosion-proof valve and a protective sheet, wherein the explosion-proof valve and the protective sheet are disposed in the second through hole, the explosion-proof valve is spaced apart from the protective sheet, the explosion-proof valve is disposed closer to the second surface than the protective sheet, and the explosion-proof valve is configured to seal the second through hole; wherein the pole comprises an abutting portion and a pole body connected with each other, the abutting portion is disposed in the first recess and abuts against the carrier portion, the pole body exceeds the first surface, the second through hole penetrates through the abutting portion and the pole body, and the second through hole penetrates through a surface of the pole body away from the abutting portion; and wherein the second through hole comprises a first through sub-hole and a second through sub-hole that communicate with each other in a bent manner, the first through sub-hole penetrates through a surface of the abutting portion away from the pole body, the explosion-proof valve is disposed in the first through sub-hole, the second through sub-hole penetrates through a surface of the pole body connected with the abutting portion, and the protective sheet is disposed in the second through sub-hole.