The present disclosure provides a cap assembly for a secondary battery and a secondary battery. The cap assembly includes a cap plate, a fixing member, a connecting member and an electrode terminal, wherein the cap plate has an electrode lead-out hole; the fixing member is fixed to the cap plate through the connecting member and provided with a weakened portion that is close to a center line of the cap plate in a width direction of the cap plate; and the electrode terminal includes a terminal board, wherein the terminal board has an outer peripheral surface at least partially surrounded by the fixing member so that the electrode terminal is fixed to the fixing member, and the terminal board is provided on a side of the cap plate and covers the electrode lead-out hole.