Abstract: In the case where the execution mechanism or information network of the power unit of the electric multiple units malfunctioned, resulting in complete loss of power for two power units, this paper applies the controlled Lagrange method to achieve speed stabilization control and displacement stabilization control for this system.Firstly, a multiparticle nonlinear dynamic model of the EMU（electric multiple units） is established, and the controlled Lagrange equation is constructed using the expected controlled energy.Secondly, the matching conditions between the controlled equation and the original equation are clarified and simplified due to the neglect of the gyroscopic force term.Then, by solving the partial differential equation, the expected displacement condition that can stabilize the velocity is found, and a smooth feedback controller is obtained.Then, the controlled energy is chosen as the Lyapunov function, and the asymptotic stability is proven using LaSalle’s invariance principle.Finally, the feasibility and effectiveness of the controller are verified through simulation using the CRH3 EMU as the research object.The controller ensures that the EMU can safely decelerate after a failure and operate smoothly at low speeds until it finally comes to a precise stop at its destination.