The outer layer is a 304H heat-resistant steel protective tube capable of withstanding instantaneous high-temperature shocks up to 1300°C. The middle layer, an alumina ceramic fiber layer, prevents internal gas corrosion. The inner layer's reference gas self-purification device can filter particles larger than 20μm, extending the average service life of the probe under continuous carburization conditions to 18-24 months. A microcrystalline silicon carbide coating is applied to the measurement electrode surface, effectively reducing the rate of carbon black deposition, extending the maintenance cycle from every 200 hours to 600 working hours for the conventional probe.