Lower trigeminal neuralgia should be correctly described as trigeminal neuralgia occurring in the mandibular branch. In this type of disease, first of all, the MRI of the head must be perfected to clarify the cause of the disease. If the cause of the trigeminal neuralgia of the mandibular branch is secondary, such as a tumor or vascular disease, the cause must be treated, that is, by surgical treatment of the tumor or vascular disease. If it is primary trigeminal neuralgia of the mandibular branch, medication can be used in the early stage of treatment, and the main drugs that can be chosen are carbamazepine and phenytoin sodium. If the medication is not effective, we can also consider closed treatment and radiofrequency coagulation of the semilunar ganglion. If the symptoms do not improve or recur after the above treatments, microvascular decompression surgery for trigeminal neuralgia can be considered.