Abstract: With the continuous improvement of the requirements for flexibility and flattening of industrial control systems, the traditional industrial control network based on PLC is limited in the aspects of large-scale access, computing power enhancement and deployment flexibility. To address these problems, a cloud PLC system architecture based on 5G and multi-access edge computing was designed by integrating 5G network and edge computing technology, and the operating mechanism and key technologies involved were expounded. This architecture can make full use of the fast and stable data transmission capabilities of 5G networks and data processing capabilities of edge technologies to improve the security of data storage and transmission; On this basis, the cloud deployment and debugging of PLC systems can be realized, and thus the integration of enterprise data centers, 5G networks and edge networks is achieved; Finally, the validity of the proposed architecture is verified through the application in the production line upgrade project of an automobile manufacturing company.