The present application relates to the field of an energy storage device, and more particularly, to a top cover assembly of a secondary battery, the secondary battery and an apparatus using a battery. The top cover assembly includes: a top cover sheet provided with an explosion-proof hole; an explosion-proof sheet, a position of the explosion-proof sheet corresponding to the explosion hole; and a fixing member, at least part of the fixing member being located between the top cover sheet and the explosion-proof sheet and connecting the top cover sheet and the explosion-proof sheet; where one of the explosion-proof hole and the fixing member is provided with a protrusion and the other is provided with a first groove, and the protrusion and the first groove are fixed.