Abstract: Open arc welding robot has been widely used in metallurgical industry,and the transmission accuracy of each component inevitably causes cumulative errors on running accuracy of the welding gun head and influences the welding quality.Therefore,how to improve the driven accuracy and control manufacture errors are key problems in welding robot design.In this paper,a virtual model of open-arc robot was built based on ADAMS/View,and after motion simulation, the robot dynamic characters were obtained in welding process.The results show that this new method was simple and highly accurate,without needing to establish complicated mathematic model,largely improves the design efficiency.