Abstract: The pipe welding maintenance in nuclear environment requires the teleoperation method to be accomplished.According to the feature of the pipe maintenance in nuclear,the teleoperation control system was studied on the basis of the self-developed minor-caliber pipe welding device.The system was composed of the industrial computer in which the PC-6501D card was inserted.The signal of motor drivers was sent by the VC++6.0 programs to realize the motion of the whole system.To ensure the stability of the arc length during the all position welding and improve the quality of the welding,the close-loop feedback of the arc voltage was added in this system.Results show that the velocity and direction of the all position welding can be adjusted in this control system,moreover,the difference of the arc voltage was less than ±0.2 V under the control of the arc length feedback.The actual welding results are satisfying.