3d printer and control method thereof

The invention relates to a 3D printer and a control method thereof. By the adoption of the 3D printer and the control method thereof, the defects of the prior art are overcome. According to the technical scheme, the 3D printer comprises a feeding mechanism, input equipment, a displayer, a memorizer, an upper computer, a printing control chip, a temperature monitoring sensor, a temperature increasing device and a spray volume control valve. The upper computer is electrically connected with the input equipment, the displayer, the memorizer and the printing control chip. The printing control chip is electrically connected with a motor, the temperature monitoring sensor and the temperature increasing device. A 3D printing spray head comprises a spray head controller, a supply mechanism, a wire melting mechanism, a wire feeding mechanism, a passageway, a sizing device and a nozzle. The spray volume control valve is installed on the nozzle. The input end of the supply mechanism is connected with the feeding mechanism. The output end of the supply mechanism is connected with the input end of the wire melting mechanism. The output end of the wire melting mechanism is connected with the input end of the wire feeding mechanism. The output end of the wire feeding mechanism is connected with the input end of the sizing device through the passageway. The output end of the sizing device is connected with the nozzle.