In the three-wire welding system, a welding process consists of the operations of four devices, namely three welding machines and one bogie. The operations need to be synchronized by a numerical coordinate controller (NCC). In this paper,we will discuss a task-job-procedure cubic program structure. Under this structure, the devices are synchronized and isolated at the same time. This cubic program structure can also be used as a reference for other multi-device or multi-unit manufacturing processes.