The common Os may occur in molybdenite as substitution atoms, therefore the molybdenite containing high content common Os has possibility in principle. Many analysis results demonstrate that high content common Os in the molybdenite may significantly affects the Re-Os model age. For most of molybdenite, the influence of common Os on the Re-Os model age cannot be ignored in case of OsCommon /¹⁸⁷Os Total<20,  and the Re-Os model age should be calculated based on the method given in the paper rather than directly using the decay formula.¹⁸⁷Os/¹⁸⁸Os-¹⁸⁷Re/¹⁸⁸Os isochron is made to obtain the initial ¹⁸⁷Os/¹⁸⁸Os value, then the non-radiogenic ¹⁸⁷Os in total Os is obtained according to the initial ¹⁸⁷Os/¹⁸⁸Os value and single sample common Os content. Model age is got according to the Re content and radiogenic ¹⁸⁷Os content finally.