PURPOSE: A seal valve device with an automatic closing function for a blast furnace is provided to prevent the backflow of internal pressure of a furnace into a furnace top hopper by pressing a metal seat against a packing. CONSTITUTION: A seal valve device with an automatic closing function for a blast furnace comprises a temperature sensor(210), a control unit(220), and an actuator(230). The temperature sensor is installed on the outer side of a metal seat(120) located adjacent to a packing(111). The control unit compares an electric signal transmitted from the temperature sensor with a reference value and outputs a control signal when the electric signal is equal to or greater than the reference value. The actuator provides an external force to the metal seat according to the control signal of the control unit to press a sealing unit(121) against the packing and enhance the airtight seal between the sealing unit and the packing.