The process of a ingot remelting in a Consarc coaxial electroslag remelting (ESR) furnace is regarded as a timevarying system. First the detail introduction of the control system for Consarc ESR furnace is given. Then the part of melting rate control is discussed as the key point of the system. A timevarying model is identified from the melting process and is used as part of the control system. Finally a new control system for the Consarc ESR furnace is developed, and used in a Consarc ESR furnace with 15 t weight in a plant of XingTai metallurgical roller Group. After 6 months operation, the new control system shows steady and good performance, and some features of this system are even better then the old one.