Button cell and preparation method of button cell

The invention discloses a button cell and a preparation method thereof. The button cell comprises a negative electrode cover, a positive electrode shell, a sealing ring, a positive electrode, a separator, a negative electrode and electrolyte, a positive electrode light sheet comprises a through hole penetrating through the positive electrode light sheet in the radial direction, the side, close toa positive electrode ring, of the through hole is flush with the inner surface of the positive electrode ring, the outer surface of the positive electrode ring is connected with the inner surface of the positive electrode shell, and the inner surface of the positive electrode ring is welded through the through hole so that the outer surface of the positive electrode ring and the positive electrodeshell can form welding points. According to the button cell, the through hole is formed in the positive electrode light sheet; welding can be achieved from the inner surface of the positive electrodering, so that welding poin