PSD-BPA calculation software is an essential tool for electric power planners. With the rapid development of Chinas power grid， the advance of smart grid and construction of UHV AC/DC transmission network， the setup of national network architecture has gradually formed. Owing to the single integrated application environment， low degree of intelligence， inefficient result application and other shortages of traditional PSD-BPA software， the efficiency of electric power planning and design is affected. In order to enhance computational tools and improve work efficiency， PSD-BPA based stability calculation of the power flow analysis platform using the R&D results of the online pre-decision system is developed. A platform based on PSD-BPA is developed for grid power flow stability calculation and analysis with such new functions as the advanced power grid analyzing function to off-line platform， friendly man-machine interface， highly efficient power modeling， automatic multi-core parallel calculation， and intelligent auxiliary analysis of decision-making integrated into an organic whole. Wide engineering application shows that the analysis platform is user-friendly， intelligent and efficient with fast calculation and correct and effective decision support.