The invention discloses a decommissioned power battery centralized monitoring system comprising a BMS slave board, a BMS main board, a battery box, a station-level monitoring system and a charging anddischarging module, wherein the BMS slave board acquires the state data of each battery cell in the battery box, and transmits the state data to the BMS main board; the BMS slave board and the BMS main board have a flexible many-to-one mapping relation; the BMS main board transmits the received state data to the station-level monitoring system; the station-level monitoring system processes the state data to determine an optimal charging and discharging strategy and adjust the current charging and discharging strategy of the charging and discharging module according to the optimal charging anddischarging strategy. It can be seen that the monitoring system provided by the embodiment dynamically adjusts the charging and discharging strategy according to the battery state information of thewhole station and the charging and discharging requirement of the system, and can utilize the decommissioned power battery to the utmost extent. In addition, a real-time control unit is disposed in the station-level monitoring system to achieve centralized processing and analysis, and then to accurately determine the battery state and improve monitoring accuracy.