Abstract: The calibration of welding robot system is the premise condition to promote intelligent level, improve the efficiency of welding and ensure the welding quality. A great deal of fruitful research works had carried out by many scholars at home and abroad for the research on calibration of welding robot system. According to different calibration object, the calibration of welding robot system is divided into four categories, the calibration of the welding robot body, the calibration of tools, part calibration and collaboration system calibration. The deficiency of the existing technology and the future development trend of calibration technology were proposed by the brief introduction of the respective calibration on the basis of principle and specific methods to promote the further development and application of the calibration technology of welding robot system.