Abstract: To solve the welding questions of reinforcing plate for large diameter percussive drill bit and tapered steel pipe, an automatic feeding and welding equipment of reinforcing plate is developed. The automatic feeding device and the control system were designed. This whole equipment consists of frame, feeding device, clamping and distance measuring device, welding gun moving device, welding machine, control cabinet etc. The control system includes detection part and control part. The former was used to detect the rotation of the tapered steel pipe to determining the weld position of the reinforcing plates. The later controls the motion of the welding gun to realize the welding of the reinforcing plates. This equipment can improve the welding automation level of reinforcing plate, reduce the labour strength of worker and increase the welding efficiency.