Maglev system is nonlinear and unstable essentially. It is complicated to design a stable system, especially when the system is under largescale disturbance and parameter variance, which make the system lose stability and emanation easily. Theoretical analysis and experiments show that this phenomenon is due to the HOPF bifurcation in the mathematical model. This paper gives an adaptive control law, which adjusts PID control parameters of the nonlinear system according to the HOPF bifurcation. Through discrimination of the disturbance and object parameters, the controller adjusts the feedback coefficients to make the system far from the HOPF bifurcation point and maintain the stability of the magelv system. Simulation result by changing mass suddenly indicates that adjusting proportion gain parameter using this method can magnify the state stability range of the maglev system and reject the selfexcited vibration efficiently.