The idea and method of controlling complex dynamic behavior of a rotor-bearing system, i.e. bifurcation and chaos, is given in this paper. A controller of the controlling bifurcation and chaos is designed by washout-filter feedback method. Characters of the bifurcation and chaos are improved according to above method. The stability of a rotor system is controlled by modulating the parameters of this controller. Numerical simulation result show that, the dynamic behavior is changed rapidly along with the rotate speed of the rotor-bearing system increase continued. The washout-filter feed back method has a good effect on controlling bifurcation and chaos in above condition.