According to the variable structure theory, presents a second-order dynamic sliding mode controller with stronger robustness to achieve precise control of the magnetic levitation ball system, in which the higher derivative of the new switching surface reduces the impact of the discontinuous terms in the reaching law and improves the defect of serious chattering existing in common sliding mode controller. Through the simulated comparison to the common controller, it indicates that the designed controller gets system better dynamic performance and achieve system steady levitation