Abstract: With the demands of high reliability of power supply, the way that the high voltage breaker maintenance by poweroff hasn't been able to meet the breaker's state evaluation requires. So for solving this problem, one kind of high voltage breaker action characteristics online monitoring device is introduced.With the analysis of cases, assess the conditions of the high voltage breaker and setup the "fingerprint database"-the breaker's opening and closing current wave form.Using the advanced algorithm analysis technology to analyze on line and give an abnormal alarm.judge the breaker's running state for date support of the maintenance strategy.Find and deal with the defeats and abnormal conditions to make sure the power system operating safely and stably.