In view of the flame cutting machine was required to realize some functions in processing process, such as back to zero, control shaft initialization, processing pretreatment, continuous track motion control, the mode of “PC+motion controller” open system structure was presented. After analyzing the working principle of the “PC + motion controller” mode,on the basis of the function library of GE200SG motion controller, Visual C++60 development environment, the class definition, encapsulation and inheritance technologies were used to develop the motion control module.