Surface crack defects are dangerous forms of defects in materials,and it is important to detect surface cracks generated during service in time.Laser infrared thermography not only has the advantages of traditional infrared detection,but also has the unique advantage of high laser energy density,which can detect micro cracks on the surface of materials.The effects of laser infrared thermography system platform components and their key parameters on laser infrared thermography detection are reviewed in the paper.From the perspectives of image processing and optimization of process parameters,the qualitative identification of surface crack defects detected by laser infrared thermography is expounded,and the quantitative characterization of the length,width and depth characteristics of surface crack defects is further introduced.Finally,the paper summarizes the surface crack defects detected by laser infrared thermography,and looks forward to its future development direction.