Abstract: Six multivariable self-tuning control algorithms are discussed and their different characteristics are compared.Hereby some reference opinions on Selecting self-tuningcontrol algorithms of plant model are given.Furthermore,a computer aided design soft package of the above multivariable self-tuning control algorithms is introduced,with its design idea,program structure,function and basic features explained.It hasactually been used for instance to design a temperature control system for a group of annealing furnaces in an iron and steel plant.