Protection circuit for cooking electric appliance

A protection circuit for a cooking electric appliance comprises a square wave drive control circuit, a ground wire loop control circuit, a door opening and closing detection circuit, a processor MCU and a microswitch K1, the square wave drive control circuit comprises a first drive circuit and a second drive circuit, and the processor MCU is connected with the first drive circuit, the second drive circuit and the door opening and closing detection circuit. The first end of the microswitch K1 is connected with a ground wire, the second end of the microswitch K1 is connected with the door opening and closing detection circuit and the ground wire loop control circuit, and the ground wire loop control circuit is connected with the first drive circuit and the second drive circuit. The microwave of the microwave oven can be successfully started only by ensuring that the microswitch K1 is closed, the door opening and closing detection is successful, the triode Q1 controls output, the triode Q3 is conducted and the t