Abstract: Using non-contact eddy current sensors for seam tracking,the linearity of the exponential circuit compensation was applied to increase the range of the sensor and eliminate the distortion during seam tracking.The automatic tracking of the flat butt I-shape groove of complex shape seam was realized with the swing type eddy current sensor detecting the deviation information of the weld seam.Using the regional integration differential weighting method to analyze the welding seam deviation information,the misjudgment due to the uneven thickness and dislocation was eliminated with the sampling data points unchanged and the seam tracking accuracy was improved.The experiments showed that the swing eddy current sensor was feasible and effective and provided a new approach for automatic seam tracking.