Maintaining the running and continuous improvement of EN 15085 welding system is very important for the welding manufacturers of railway vehicles and components.With the higher and higher requirements on welding quality of products,how to let more employees master and participate in the operation of the welding system has become an issue for enterprises. Not only does this article analyze the key points of the implementation of man,machine,material,method,enviro-nments and traceability in the running of the welding system,but also it summarizes the common problems in welding coordination,weld joint design,production weld tests,certification level CL 4 and certificate application,and puts forward suggestions for improvement. This article provides feasible guidance for enterprise personnel to understand and maintain EN 15085 welding system.