At present, China's washing machine market is entering a renewal period, with great market potential, and people's requirements for washing machines are getting higher and higher. At present, the washing machine mainly has seven functions, such as strong and weak washing function, automatic diagnosis function of inlet and outlet system and pause, which can not meet people's various needs. This requires designers to have a higher professional and technical level, be able to put forward more good suggestions and new topics, turn people's needs into reality, and design more energy-saving, more comprehensive and more humanized automatic washing machines. At present, washing machines are incompatible in all aspects. Most washing manufacturers pay attention to the specialty of their own brand washing machines, highlighting one or two personalized functions that are different from other washing machines. The function of washing machine is controlled by PLC, and the control function is flexible. Therefore, it is very practical to design an automatic washing machine control circuit system based on PLC.

This design adopts Mitsubishi as the control core, and designs a buzzer alarm circuit to ensure the safety of the washing machine and people. This paper also introduces the PLC control system of washing machine, the basic structure and hardware design of automatic washing machine, and focuses on the PLC design of Mitsubishi automatic washing machine. In order to facilitate readers to understand and be familiar with this design more quickly, as basic knowledge, some common basic functions of PLC related to automatic washing machine are also introduced to make automatic washing machine more intelligent and perfect.