Abstract: A method of non contact and real-time measurement for XeF2 pressure in the XeF laser cell is provided in this paper.The absorption cross section of XeF2 at wavelength of 253.7nm σ253.27XeF=(1.55±0.05)×10-19cm2 is obtained.Using the same measurement system,the suitable laser tube materials is choosed and the relations between laser output energy and the pressure of XeF2 are presented.