Abstract: For fast time-varying system, based on the all - coefficient adaptive control method, presents a self-tuning controller by means of the normalized model method. The auto-regulation weighting factor is introduced into the generalized minimum variance self-tuning control law in order to fit in with the markedly changing dynamic characteristics of fast time-varying system. Digital simulation shows that the controller is satisfactory for fast time-varying system. The controller has simple algorithm and strong robustness for nonlinear, mismatched order and unmodeled disturbance of the process.