The invention discloses a blast furnace airtight box water cooling device and belongs to the technical field of blast furnace top feeder apparatus water cooling. The blast furnace airtight box water cooling device comprises an airtight box, a water supply pipeline, a water return ring pipe, a water return communicating pipe, a gas communicating pipe, a gas-water separation tank and a water return pipeline. The water supply pipeline and a water inlet of the airtight box are connected, and the water return ring pipe is connected with a water outlet of the airtight box. The water return ring pipe is connected with the gas-water separation tank through the water return communicating pipe. The water return ring pipe, the gas-water separation tank and an external communicating opening of a gas medium on a vertical water trough of the airtight box communicate through the gas communicating pipe. The water return pipeline is connected with a water outlet of the gas-water separation tank. The blast furnace airtight box water cooling device has the beneficial effects that the device is an open loop device and is simple and compact in structure, small in power consumption, easy to run, operate and maintain and high in safety.