As an important branch of metal additive manufacturing(AM), laser repair is one of the core technologies in strategic emerging industries such as equipment remanufacturing. The breakthrough of laser repair technology and its application in key fields such as aerospace and national defense equipment are in line with the strategic needs of the country and have attracted the attention of many researchers. The results show that the laser manufacturing process is complex and the environment is extreme, and the evolution of stress and strain field affects the defect distribution and geometry of the restoration, which is the key factor to determine the repair quality. Under this background, traditional detection methods and technologies are difficult to be directly applied to laser repair engineering, so it is urgent to develop detection technologies suitable for laser repair engineering. At present, there is a shortage of measuring means to match the repair manufacturing equipment, so the key problems and common detection techniques in laser repair are investigated and studied in this paper.