Graded propellant powder chamber pre-ignition launching device and method for fire extinguishing bullet launching

The invention discloses a graded propellant powder chamber pre-ignition launching device and method for fire extinguishing bullet launching. The device comprises a launching tube, propellant powder, apiston, an ignition device, a fire extinguishing bullet, a primary propellant powder chamber, a fire transferring device, a sealing ring, a support frame and a secondary propellant powder chamber. The method comprises the steps that the propellant powder is loaded in a serial split charging mode, the propellant powder in the front secondary propellant powder chamber is ignited through the ignition device to burn, generated propellant powder gas pushes the fire extinguishing bullet to move forwards, and the piston is kept still under the action of the support frame; when the pressure in the secondary propellant powder chamber reaches a set value, the propellant powder in the primary propellant powder chamber is ignited through the fire transferring device; then the piston moves forwards under the action of pressur