The invention provides an air-cooled thermocouple verification furnace with an insulation layer and a preparation method thereof, comprising a verification furnace body, a furnace tube, an insulation isolation tube, an electric heating wire, an insulation layer, an air-cooled tube, a high-speed exhaust fan, an exhaust window, an air intake window. Its advantage is that four air-cooled pipes are arranged symmetrically in the insulation layer, and a high-speed exhaust fan is installed at one end of each air-cooled pipe, which can efficiently discharge the heat stored in the insulation layer of the thermocouple verification furnace, thereby rapidly reducing the temperature of the thermocouple verification furnace. temperature, which improves the utilization rate of equipment, greatly improves the efficiency of thermocouple verification, and is easy to manufacture and use, without any auxiliary operation, which is conducive to the automation of the production process.