Deep caries has produced certain pulp symptoms, such as tooth sensitivity, tooth pain and pain from hot and cold stimulation, due to the large extent of decay and destruction, which is closer to the nerve. In this case, the decayed and necrotic tooth tissue should be removed first, while the pulp is capped and the nerve is appeased by using pulp capping drug, the clinically applied drug is calcium hydroxide. After the treatment is completed, hot and cold irritating foods should be abstained and used to protect the pulp, and a clinical follow-up should be performed in about a month’s time. If the toothache, tooth sensitivity, and hot and cold irritation pain disappear, the nerve is successfully pacified and can then be permanently filled with a dental filling material. If the nerve symptoms do not disappear and there is still tooth pain, hot and cold irritation, and increased pain, then the nerve has failed to be pacified and pulp therapy is required before permanent filling of the affected tooth.