Abstract: According to the design principle of model reference identification,an improved method is presented for the cascade control system with pure time-delay.The secondary control object is regarded as an identification process,the Smithpredictor is tuned online by the adaptive identifier with the help of generalized error e,and the coherence of dynamicity is maintained between the Smith-predictor and the secondary control object.At the same time,a reference model is set for the master control object based on the expected performance index,and the system has a satisfactory output even when the master control object changes.The simulation examples are given to illustrate the effectiveness of the proposed approach.