The experiment research on damage in K9 glass induced by pulsed CO2 laser is carried out, which has a pulse width of 10 μs. The theoretical model of K9 glass irradiated by pulsed CO2 laser is developed and a numerical simulation is performed to calculate temperature and stress distributions in K9 glass sample irradiated by pulsed CO2 laser using finite element method. The simulation and experimental results indicate that the damage-threshold of K9 glass irradiated by single pulse is 6.533J/cm2, and the effect of laser irradiation on samples can be affected considerably by the change of laser energy density. The damage mechanism of K9 glass induced by pulsed CO2 laser are melting damage and compress stress damage in irradiated zone, and the damage mechanism of K9 glass induced by pulsed CO2 laser is circular tensile stress damage in the periphery of irradiated zone when the laser energy is high. The model prediction agrees well with the experiment data.