To support the improvement and development of CRH (China Railways High-Speed) trains, a virtual development platform is set up for high-speed train traction drive system. The traction drive system of CRH2 EMU (electric multiple unit) is described. A design idea based on top-level goals is proposed in this paper and has been used in the platform. Aiming at CRH380A, traction drive system design around the maximum operation speed is shown with some simulation results.