Abstract: Because V01 arc-welding robot controller has closed structure and can not be capable of off-line programming and integrating external sensors,a PMAC-based open architecture robot controller for the V01 arc-welding robot was designed in this paper.The architecture of control system consists of layered structure and functional unit was presented.According to the architecture presented,the hardware structure of servo system and control system was designed.Control software was developed by means of objective-oriented technology and the modular.