Abstract: Due to the large number of heat transfer tubes, manually checking the position of the probe during the inspection process takes a long time. CITEC has developed a machine vision positioning system. The system can monitor in real time during the inspection process and help to check the current position. The system has been tested in the laboratory for a long time and also has been used on site. It has good results, high accuracy and stability. It can meet the needs of on-site use, and improve the efficiency and reliability of eddy current inspection of heat transfer tubes.