Dental fear is an abnormal psychology, physiology, and behavior exhibited by some people during dental treatment. Clinical manifestations of dental fear include rapid heartbeat, abnormal blood pressure, sweating, use of umerous words during speech, muscle tension, pale complexion, and syncope. Midazolam exerts anti-anxiety, sedative, hypnotic, anticonvulsive, and muscle-relaxing effects. Patients under midazolam may exhibit brief anterograde amnesia and may forget what happens during the drug peak. Major side effects of midazolam include cardiac arrest, heart rate change, allergic reaction, thrombosis, laryngospasm, bronchospasm, respiratory depression, and respiratory arrest. Minor side effectsof this drug include burping, nausea, vomiting, headache, dizziness, bed-wetting, hallucinations, dizziness, diplopia, and transient oxygen desaturation. Thus, analyzingthe side effects of midazolam and establishing a database of these side effects are necessary to provide guidance during the clinical application of midazolam.