Abstract: A multivariable predictive functional control algorithm is presented,which is a branch of model predictive techniques family.It is deduced with the theory of predictive functional control and Smith predictor,and is the extension of single variable predictive functional control.A computer simulation case study for the control of Shell Oil's heavy oil fractionator is presented.The result displays that the presented multivariable predictive functional control algorithm is of better control performance than the single variable predictive functional control in the multivariable first order plus dead time system.