A multi-purposes mechanism for shooting apparatus includes a gun body, a barrel, a shooting member, and a rear cap. The gun body comprises a hollow tube perpendicularly interconnecting with a first loading hole at a center portion of the hollow tube. A first stage is formed on an inner wall of the tube in front of the first loading hole. A second stage is formed on the inner wall of the tube in back of the first loading hole. The barrel is disposed in the tube before the first loading hole, and has a first engaging ring corresponding to the first stage of the tube. The shooting member is disposed in the tube after the first loading hole, and has a second engaging ring on an outer wall thereof corresponding to the second stage of the tube. The rear cap is connected to a rear end of the tube.