As the common laser processing methods such as ultrashort pulse laser processing,laser induced plasma processing,nanosecond ultraviolet laser processing have low corrosion rate for quartz glass,a new etching method for quartz glass is proposed,and it has the characteristics of wide range,high corrosion rate and low fracture.The etching mechanism of laser induced chemical reaction with different energy densities was analyzed.The experiment shows that the quartz glass can be etched when the laser energy density is more than 16 J/cm2.When the laser energy density is between 16~24 J/cm2,quartz glass is corroded by the only physical mechanism,thus,the change of etching rate is low with the change of laser energy density.When the laser energy density is between 24~42 J/cm2,the change of etching rate with the increasing of laser energy density is comparatively large.The main reason is that the chemical reaction of SiO2 with both Ba(OH)2 and BaO are generated at high temperature and BaSiO3 is produced.When the laser density is between 41~46 J/cm2,the rate of chemical reaction is nearly maximum,so the etching rate increases slightly with the increase of laser energy density.