Abstract: The welding system is one of the important subsystems of an arc-welding robot. A welding system which has not been designed to meet the special requirements of robotic welding production will be no good in application.This paper presents both an analysis of the characteristics of the robotic arc-welding system and a study of its functions and construction.An introduction to the design of the HY-I Robotic Arc-Welding System is also given.