The invention discloses a circumcising device comprising a lower fixed ring, an upper fixed ring and an incision gun, wherein the lower fixed ring and the upper fixed ring are coaxial and have the same diameter; the incision gun comprises a shell, a driving ring and a transmitting system; a sliding chute is arranged in the shell; a gunpoint is formed in one end of the sliding chute; and the driving ring is clamped in the sliding chute and is connected with the transmitting system. The driving ring is composed of an adhesion ring and an incision ring, wherein the incision ring is located inside/outside the adhesion ring and is coaxial with the adhesion ring, and one end of the driving ring is connected with the transmitting system, so that the driving ring can be popped up along the direction of the sliding chute. By using the circumcising device, the wound is small, the pain of a patient is little, and the wound cannot bleed and is not needed to suture.