Laser cleaning technology is a new rapidly developing cleaning technology in recent ten years. With its advantages, it has gradually replaced traditional cleaning technologies in many fields. The pulsed Nd:YAG laser cleaning process depends on laser pulse characteristics generated by lasers. Based on the photophysical reaction caused by the interaction among high intensity beam, short pulse laser and pollution layers, the basic principle and classification of Nd:YAG laser are introduced, and the principle of laser cleaning is imposed. The Nd:YAG laser cleaning experiment is also introduced. Experimental results show that Nd:YAG laser cleaning has good effect on cleaning the surface of smooth substrate, which is a developing direction of cleaning technology in the future.