The invention relates to a
microwave plasma chemical vapor deposition (MPCVD) synthesis device, a control method and a synthesis method. The synthesis device comprises a
microwave generating device, areaction cavity and a
gas supply device. The synthesis device is characterized in that the synthesis device further comprises a
microwave reflecting measuring device, a temperature measuring device,a vacuum measuring device, an
atmospheric pressure control device and a control center, wherein the microwave generating device, the microwave reflecting measuring device, the temperature measuring device, the vacuum measuring device, the
atmospheric pressure control device and the
gas supply device are separately connected with the control center in a communication mode. According to the
microwave plasma chemical vapor deposition (MPCVD) synthesis device, the control method and the synthesis method, by automatic matching of power,
atmospheric pressure, temperature and reflecting microwave,
dynamic balance is realized, the internal environment of the reaction cavity can be stabilized in the environment which is most suitable for the synthesis of a target product, and the synthesis rate andquality of the target product can be improved; through the automatic matching of the power, atmospheric pressure, temperature, and reflecting microwave, the operating efficiency of the operator is effectively improved, and the time and labor is achieved; and the use efficiency of a magnetron is effectively improved, and the use safety is ensured.