In view of the problems that unclear source, loose connection with other system requirements and over-reliance on professionals’ subjective decision-making during the quantitative requirements analyzing with MBSE traditional methodology, this article aims to study the method about defining performance indexes based on functional requirement and adding general design element into MBSE model. The process and source of requirement analysis of each level indexes are also defined in this study. By means of scaling up the CPU time and integrating the representative disciplines models into MBSE functional logic model, the requirements of quantitative indexes can be verified by the integrated simulation. The feasibility of the improved methodology and modeling method is validated through the modeling and simulation practices on MagicDraw software.