The treatment of prolonged QT interval is mainly dealt with according to its specific situation, which mainly includes regular review, medication and non-pharmacological treatment. Long QT interval can be categorized into congenital QT interval prolongation and acquired QT interval prolongation. The causes of acquired QT interval prolongation include drug effects, cardiac diseases, and central nervous system dysfunction. Patients may present with palpitations, arrhythmias and other manifestations. 1. Congenital QT interval prolongation: mainly treated by drugs, β-blocker is the first-line treatment choice. Commonly used drugs are propranolol and nadolol. A few special cases do not need to be treated with drugs, but need long-term review. 2. Acquired QT interval prolongation: in addition to treatment with β-blockers, potassium supplementation should be actively used. If tip-twisting ventricular tachycardia is induced, intravenous magnesium sulfate should be injected. 3. If drug treatment is ineffective or the condition is serious, implantation of cardioverter-defibrillator (ICD) or left cervicothoracic sympathectomy should be considered, and pacemaker implantation can be considered for bradycardia. Prolonged QT interval may lead to malignant arrhythmia such as tip-twisting ventricular tachycardia and ventricular fibrillation, and the patient may have fainting, convulsions, and sudden cardiac death. Once the prolonged QT interval is detected, it is recommended to go to the hospital in time for early treatment to avoid irreversible consequences.