The invention discloses an easy-opening canning jar with a separate bottle cap and a separate ring-shaped unscrewing and clamping device, which comprises a canning jar body, a canning jar cap, a sealing ring, and a ring-shaped unscrewing and clamping device; and the easy-opening canning jar is characterized in that the canning jar cap and the sealing ring are separated from the ring-shaped unscrewing and clamping device, and the sealing ring is not contacted with the ring-shaped unscrewing and clamping device, so that the closed friction force of the canning jar cap, the sealing ring and the canning jar body is not overcome necessarily, and the friction coefficient of the canning jar cap and the ring-shaped unscrewing and clamping device is low, so that the canning jar cap is easy to open. The bottle cap can be made of transparent glass, and the canning jar body can be made of such materials as metal, ceramic glass and the like, so as to facilitate the food heating and the volume increasing.