Xenon（Xe） isotopes from nuclear test and accidents are important monitoring components of the comprehensive nuclear test ban treaty（CTBT）．An approach for the reproducible and accurate compositional analysis of Xe isotope ratios by multiple collector inductively coupled plasma mass spectrometry（MC－ICP－MS） was described in this paper．A Xe enrichment and purification platform was established to separate Xe from the collected atmosphere gas，enriching the Xe concentration and utilizing high purity argon as aerosol carrier，thus resulting in eliminating the negative influences of organic compound and particles on mass spectrometry．A relible Xe injection system was built to control the gas flow rate between the sample and the MC－ICP－MS in order to improve the stability and reproducibility of the ion-signals．Furthermore，several measures，including adsorbing Xe from the sample gas for mass spectrometry and baking the Xe introduction device for 2 hours with vaccum pumping，were taken to reduce the Xe blank．As a result，the blank signal of ,129,Xe falled from 3.0 × 10,-2, V to 2.7 × 10,-3, V．Analyses were performed on a Neptune XT MC－ICP－MS，and standard sample bracketing（SSB） was involved in correcting the mass fractionation．The approach was successfully validated by the measurement of standard reference materials in 24 hours，showing that the relative uncertainties for,all Xe isotope ratios were less than 0.09%（,n ,= 7），while the results agreed with the certificated values within uncertainty range．Especially，the relative uncertainties for ,130,Xe/,131,Xe and ,132,Xe/,131,Xe ratios were 0.007 1% and 0.006 9%，respectively．Two kinds of atmosphere gas collected at different times were analyzed and distinguished successfully by the proposed approcach．The results demonstrated that the developed technique was a precise and accurate method for Xe isotope dectection，Xe monitoring event identification and event sourcing.