Laser cleaning is a novel and effective cleaning technique,which uses the excellent directionality and high brightness of laser to clean the contaminants on the surface of materials, while does not destroy the substrate. In this paper, the main three cleaning principles with laser ablation, dry laser cleaning and wet laser cleaning are introduced, the mechanisms and influencing factors for dry laser cleaning and wet laser cleaning are analyzed detailedly. The laser cleaning applications in the fields of precise components, cultural relics and upsize components are also presented . Finally, an evaluating system for laser cleaning is introduced and the evaluating criterion of cleaning quality is established.