Abstract: An automatic welding system for bent angle welds was proposed based on rotating arc sensors to solve the issues of low welding efficiency of welding robots, poor real-time performance of non-contact sensing welding and insufficient tracking accuracy of low-current welding. A rotating arc sensor welding torch is designed, which induces changes in the welding current caused by the high-speed rotation of the arc to determine the position of the welding torch and achieves seam tracking. The system has three degrees of freedom in X, Y, and Z, and significantly improves the welding efficiency. The experimental results demonstrate that the system can achieve automatic welding of bent angle welds with indefinite shapes.The research not only enhances the welding efficiency, but also provides novel ideas and approaches for the development of robotic automatic welding technology.