The utility model relates to a power management monitoring device applied to an online monitoring system of power transmission lines. The power management monitoring device includes a first bleeder circuit, a second bleeder circuit, a temperature acquisition circuit, a microprocessor, an anti-reverse-charging circuit, a charging circuit, a discharge circuit, a 485 circuit, a first wireless communication module, a second wireless communication module and a master station. Beneficial effects are that the power management monitoring device can prevent a power supply fault of a storage battery and achieve the charging effects of safety, effectiveness and full capacity; reasonable use of the storage battery is utilized to prolong the service life of the storage battery, and thus various maintenance costs and labor cost due to the damage to the storage battery are reduced and the efficiency and cost performance of the system are improved; and the power management monitoring device provides reliable power supply guarantee for the wide application of online state monitoring systems of power transmission lines.