Disposable thermocouple is mainly composed of temperature measuring probe and a big paper tube. Positive wire and negative wire of the temperature measuring probe are welded to a compensating lead wire embedded in a support bracket covered by a small paper tube. The thermo wires are supported and protected by quartz. The temperature measuring probe is covered by a cap to protect from dregs. All the components are put into a thermocouple tip and are bonded by fire-resistant filler into a whole. Therefore, the fast thermocouple is for one-time use.