In the laser system, the micro-nano impurities attached to the optical glass surface will cause additional modulation of the beam, the laser beam quality and the damage threshold of the optical component will be reduced, and even the output and load capacity of the laser device will be affected. Therefore, in order to improve the stability and reliability of the optical system, it is necessary to maintain the cleanliness of the optical components. For the micro and nano pollutants on the surface of optical glass, laser cleaning is used to clean. In particular, the selection of suitable laser energy is the key to determine the cleaning effect of micro and nano particles on the glass surface. In order to achieve the ideal cleaning effect, it is necessary to study the mechanism of the interaction between laser and micro-nano particles on the glass surface. By analyzing the comprehensive effect of the action process to predict the action effect, the appropriate cleaning energy can be selected.The sample was prepared by particle deposition, K9 glass is used as the substrate, cerium oxide particles are used as the pollutants on the glass surface, and the laser cleaning experiment and analysis are carried out. For different laser energy, the micro and nano particles are cleaned in two ways: "forward" and "back". Among them, in the "forward" cleaning, the particle is located above the glass base, the laser is cleaned from top to bottom, and on the contrary, it is "back" cleaning. The cleaning effect for different energy and the thermodynamic damage of glass substrate by different cleaning methods are analyzed by experiment. At the same time, the thermal stress model of the cleaning process was established, and COMSOL was used for simulation to analyze the mechanism of the interaction between the laser and the micro-nano particles on the optical glass surface and the thermodynamic effect of the particles on the substrate.The experiment shows that the backward cleaning is better than the forward cleaning. By using the method of backward cleaning, for the laser energy of 0.815 J/cm², the large particles on the glass surface can be cleaned better. And for increasing the laser energy to 1.120 J/cm², the cleaning effect is further improved(Fig.9). The laser energy of 1.426 J/cm² causes obvious thermodynamic damage on the surface, such as pits and deformation(Fig.10). The simulation results show that for laser energy greater than 0.764 J/cm², the micro and nano pollutants with particle size greater than 1 μm can be stripped off the glass surface due to thermal stress. The glass surface is cleaned without heat damage. However, if the laser energy exceeds 1.426 J/cm², the thermal stress and shock wave generated by the thermal effect and particle temperature exceeding the melting point of the glass substrate will cause damage to the glass surface (Fig.3).The cleaning samples were prepared by particle deposition method and the laser cleaning experiments were carried out. The results indicate that the laser energy in the range of 0.815-1.120 J/cm² can achieve significant cleaning effects by using the method of backward cleaning, and there is no damage to the substrate. And for the energy of 1.426 J/cm², the obvious thermodynamic damage appears on the cleaning surface. The model of heat conduction and thermal stress between particles and substrate was established, and the comprehensive effect of laser cleaning on glass surface was analyzed. COMSOL was used for simulation, and the results showed that a good cleaning effect can be obtained when the laser energy is greater than 0.764 J/cm². When the laser energy is 1.426 J/cm², irreversible thermodynamic damage occurs on the glass surface. The comprehensive effect of laser cleaning analyzed by theory is consistent with the experimental results. Therefore, through the analysis and modeling of the comprehensive effect of the interaction process between laser and micro and nano particles, the cleaning effect of different acting energies can be accurately predicted, so that the correct laser cleaning energy can be selected to achieve the ideal cleaning effect.