Provided is a top cover structure. The top cover structure includes a top cover and a pole assembly. The top cover includes a body and an outer protrusion portion. The outer protrusion portion is ringed at the edge of the body and protrudes in a direction facing away from a cell. An end of the outer protrusion portion is provided with a welding portion. The welding portion is welded to a housing of a battery. The body is formed with an assembly hole. The pole assembly is configured to seal the assembly hole. The welding portion is disposed away from the battery cell, that is, the distance between the welding portion and the internal component of the battery is increased.