With the increasing popularity of automated manufacturing equipment in various industries,the ST high-level language was adopted to carry on the formula program design based on PLC for the large-capacity data processing and precision control of industrial control.And on the Mitsubishi software platform,offline formula program simulation based on Mitsubishi MELSEC-Q series PLC and GOT2500 series human-machine interface was achieved,to enhance the readability of the program,to shorten the project development cycle and to improve system control security and stability.