The invention discloses a modular battery replacing cabinet and a maintenance method thereof. The battery replacing cabinet comprises a cabinet body and a plurality of electric changing warehouse receipt units arranged in the cabinet body. The cabinet body is internally provided with a charging bracket, a plurality of power changing card positions are arranged on the charging bracket in array, thepower changing card positions are provided with power changing interfaces, and the electric changing warehouse receipt units are detachably mounted on the power changing card positions and connectedelectrically with the power changing interfaces. According to the electric changing cabinet, through the unitization singly of the electric changing warehouse receipt units, all the electric changingwarehouse receipt units are connected to the cabinet body quickly in a mounted mode through a connection terminal independently, the production and assembly efficiency of the battery replacing cabinetis greatly improved, when the electric changing warehouse receipt units fail, the problematic electric changing warehouse receipt units can be directly taken out for replacement, the maintenance efficiency is improved, and the operation efficiency of the battery replacing cabinet is improved; and a requirement for the location of the battery replacing cabinet is reduced, at the same time, when the battery replacing cabinet needs maintenance, the battery replacing cabinet does not need to be moved, and the maintenance efficiency of the battery replacing cabinet is further improved.