The present invention provides a valve-type
expansion wave gun, comprising a gun body and a breech block, a
powder chamber is arranged along the length direction of the gun body through the breech block, one end of the
powder chamber is connected to the
projectile passage, and the other end is formed with a gas
injection port for injecting high-temperature
gunpowder gas, a bolt body control mechanism and a
piston control mechanism are arranged on the breech block, and due to the closing of the left bolt body and the right bolt body, the bolt body control mechanism is in a locked state, and due to the
piston member pushing the left connecting rod or the right connecting rod, the locked state of the bolt body control mechanism is released. The valve-type
expansion wave gun of the present invention controls the timing of the bolt body opening, thereby reducing the
recoil impulse and
recoil force of the gun shooting without affecting the initial velocity and range of the
projectile, eliminating the complex
recoil device, and significantly improving the firing speed, reducing the chamber temperature of the
barrel during shooting, slowing down the
barrel ablation, and extending the service life of the
barrel.