The invention provides an energy-saving plastic spraying gun which comprises a plastic spraying gun main body, a powder bottle, a mixing mechanism, an air supply mechanism and a flame stabilizing device. The plastic spraying gun main body comprises a gun rod and a gun handle, the gun rod is provided with an oxygen guiding and sending channel, a powder-air-mixed guiding and sending channel and a liquid storage cavity, the oxygen guiding and sending channel communicates with the powder-air-mixed guiding and sending channel, and the powder bottle is detachably installed on the gun rod; the mixing mechanism comprises a first communication pipe, an air transition device and a screw rod; the air supply mechanism comprises a plurality of combustible gas guiding and sending pipes and a plurality of second communication pipes; and the flame stabilizing device comprises a flame stabilizing frame, an ignition device, a plurality of liquid storage pipes and a plurality of liquid guiding pipes, the flame stabilizing frame is detachably installed on the gun rod and located at air outlets of the combustible gas guiding and sending pipes, the ignition device is installed on the flame stabilizing frame, the liquid storage pipes are installed in the flame stabilizing frame, the liquid guiding pipes are in one-to-one correspondence to the liquid storage pipes, and the liquid guiding pipes make the liquid storage pipes communicate with the liquid storage cavity. The energy-saving plastic spraying gun is convenient to use and simple in structure, and energy is effectively saved.