The present disclosure provides a secondary battery and a battery module. The secondary battery includes: a shell having an opening; an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a cap assembly including a cap plate and a first electrode terminal; a lower insulator located at a side of the cap plate away from the terminal board; and a wiring board including a main body portion and an extension portion, wherein the main body portion is located at a side of the lower insulator away from the cap plate and connected to the first electrode plate, the extension portion extends into the electrode lead-out hole and connected to the first electrode terminal, the first electrode plate is electrically connected to the first electrode terminal through the wiring board, and the first electrode terminal does not extend beyond a lower surface of the lower insulator.