Abstract: In order to solve the nonlinearity of state variables, disturbance and parameter uncertainty of magnetically levitated linear synchronous motor, a H_∞ robust control method of magnetically levitated system was proposed. By electric excitation linear synchronous motor running mechanism of the magnetic levitation system, establish electric excitation linear synchronous motor suspension system of levitation force equation and the equation of motion, the state space model of suspension system is derived, in view of the nonlinear state space model, adopt the method of balance linearization for linearization, the system of disturbance rejection problem due to the design of the controller, By solving the positive definite solution of the Riccati inequality, the H_∞ robust controller of the suspension system is obtained.Finally, MATLAB/Simulink software is used for simulation research. Compared with the PI control, the results show that the H_∞ robust control method can make the electroexcited linear synchronous motor have good disturbance suppression ability.