Abstract: Frequency domain decoupling control design methods have been widely adopted for chemical and industrial multivariable processes with time delays in engineering practice, and they belong to an important research branch in the process control field. In this paper, the research progress of several decoupling control structures and their tuning methods with dominant influence in the frequency domain are briefly generalized according to the main research achievements in recent years, and their primary virtues and deficiencies are also analyzed and discussed. Then some closely related research topics required in the current chemical and industrial practice are pointed out.