There is no necessary link between occult neurosyphilis and syphilis titer, and there is no absolute titer figure, so it cannot be a criterion for diagnosing occult neurosyphilis. Diagnosis of neurosyphilis is made by lumbar puncture, cerebrospinal fluid examination of non-specific spirochete detection tests, including rapid plasma antibody test, syphilis spirochete agglutination test, if the test is positive, it suggests possible neurosyphilis. Specific spirochete serologic tests, including spirochete fixation test and fluorescent dense spirochete antibody adsorption test, can be used as a confirmatory test for neurosyphilis. Occult neurosyphilis is a chronic systemic infectious disease caused by syphilis spirochetes invading the central nervous system. There is a clear primary syphilis infection or a positive serologic syphilis test, abnormal changes in the cerebrospinal fluid examination, and the titer is not a fixed value, nor is it an indicator to judge the severity between different patients. It is recommended that patients should pay attention and go to regular hospitals for standardized examination and treatment when they feel unwell or when they have a known disease. Avoid delaying the condition and the timing of treatment.