Abstract: In order to solve the problem that the pantograph cannot maintain the bow state during the redundant switching of the CRH5 EMU central control unit, this article studied on the principle of redundancy switching and pantograph control for the CRH5 EMU central control unit intensively, analyzed the reasons why the pantograph could not maintain the bow state during the redundant switching of the central control unit, proposed the optimization strategy of redundant switching without bow reduction of central control unit. A large number of inventory car test proved that the optimization strategy could implement the function of redundant switching without bow reduction of central control unit, so as ensure the reliability and stability of EMU application.