The present application relates to a top cap assembly, a secondary battery, a battery module, and a device. The top cap assembly includes a top cap plate, having electrode lead-out hole; an electrode terminal, arranged at the top cap plate and covering the electrode lead-out hole; a current collecting member, in which the current collecting member includes a convex portion having an accommodating cavity, at least part of the convex portion is arranged in the electrode lead-out hole, and welded and connected to the electrode terminal to form a welding portion facing the accommodating cavity, and the current collecting member has a connecting hole; an insulating protection member, in which the insulating protection member is arranged at a side of the current collecting member away from the electrode terminal, and the insulating protection member includes a shielding portion and a connecting portion connected with the shielding portion.