The electric furnace temperature control system has the characteristics of large time delay and large inertia,using traditional control methods is difficult to achieve expected control effect of the furnace temperature.To address this problem,a composite control method for electric furnace temperature was proposed based on improved time-delay observer,in which a disturbance observer was combined with a time-delay observer to estimate the state variables before the time delay,then the aggregate disturbance of the system set was eliminated,the design of the sliding mode controller was simplified,the anti-disturbance capability of the system was improved and the time delay hazard was eliminated.The proposed control method was compared with GPC and Smith estimator-based fuzzy adaptive PID control through simulation.The results show that the proposed control scheme has a faster response,almost zero overshoot,better anti-disturbance capability and better robustness.