For toothache caused by pulpitis, the pain relief method is root canal treatment, which includes opening and draining the pulp, pulp inactivation, root canal preparation, root canal filling, etc. The details are as follows. 1. Pulp opening and drainage: opening the pulp under local anesthesia can quickly relieve the high pressure in the pulp cavity due to inflammation, and the pain will be relieved after the pressure is relieved, and then the inflammatory material in the pulp cavity will be drained to remove part or all of the pulp. 2. Pulp inactivation: A pulp inactivator is sealed in the root canal to gradually inactivate the pulp. 3. Root canal preparation: Remove the infected material in the root canal system and prepare the root canal into a shape that is conducive to flushing, sealing and filling. 4. Root canal filling: The root canal is tightly sealed with root canal filling material. Crown restoration is recommended for teeth after root canal treatment, and it is recommended to go to the hospital in time to receive regular treatment.