The invention relates to a short-term reliability evaluation method of a high-voltage breaker. The current and recent reliability of the high-voltage breaker is evaluated accurately and quantitatively by a fault tree and fault mode evaluation model via data acquired by all detection means of the current breaker, including routine patrol, special patrol, preventive test data, diagnostic test data, basic standing book information of equipment, equipment defects over the years, fault records and the like. The method for evaluating the reliability of the high-voltage breaker has the advantages of conciseness, intelligibility, accuracy, visuality, quantification and the like.