Electromagnet fault can change the physical parameters of suspension control system, and even can influence
the stability of the suspension system. Therefore, in order to keep the maglev train in a high reliability, electromagnet fault
diagnosis and its fault tolerant control are proposed. A diagnosis algorithm which regards the electromagnet fault as input
variation is presented, which can not only detect the failure, but also denote the influence of faults on the suspension control
system in a scalar quantity way, and represents the fault percent of the electromagnet. Simulations and experiments show the
effectiveness of this method.