The invention provides an arrester and state discriminated method of online monitoring meter thereof, the online monitoring meter of the arrester is observed whether to indicate the electric current in a balance mode, if imbalance, the arrester is abnormal or the online monitoring meter of arrester is abnormal, the voltage of the online monitoring meter is tested, the voltage and the degree of balance are measured for judging whether the arrester or the online monitoring meter of arrester is abnormal. The power is continuously offered during the operation process, the abnormal state of arrester and the online monitoring meter can be judged timely, the state discriminated method is suitable for judging the state of arrester and the online monitoring meter during the inspecting process for operation staff, the power distribution reliability is raised for popularization and application widely.