Because the user's programming habits are taken into account, the PLC programming language is easy to understand. There are three programming methods in CCW programming software: function block, ladder diagram and structured text. The ladder diagram is relatively intuitive, and it is relatively easy for technicians to understand and master, without professional language skills. Therefore, the ladder diagram programming language is frequently used in PLC. This paper also chooses the ladder diagram programming language, and some custom modules are integrated into the structured text mode.