Focusing on the intrinsic mechanism, research progress in laser conditioning of optical materials is reviewed. In terms of material types and laser parameters, theoretical and experimental conditioning results are concluded and analyzed. As a result, the conditioning effects is determined by the evolution rule of defects under heat. Three quantitative models are discussed in detail. Their merits and demerits are compared, and the modeling tendency of conditioning is pointed out. Finally, the direction of future work is introduced considering problems such as novel research methods, industrial application and improving conditioning gain.