In this paper, Computer control of a group of electrically heated furnaces with a multivariable Self-tuning regulator is discussed. It includes the modelling of electrically heated furnaces, the design of multivariable self-tuning regulator, the study of system simulation and the analysis of real time control. Operation result shows that STR can adapt to slow variations of parameters and the control accuracy is about (800?)℃, which is better than that of PID and LQG regulators.