BAS control system of urban railway system and method thereof

The invention discloses a BAS control system of urban railway system and a method thereof. The BAS control system comprises a station level integrated monitoring system network and a BAS field level network, wherein the station level integrated monitoring system network is provided with a redundancy scheduling module, the BAS field level network is in a double loop network structure and comprises at least two redundancy PLCs and a redundancy scheduling module, the redundancy PLCs are divided into a main PLC and a spare PLC and are connected to the station level integrated monitoring system network through the loop network, and the redundancy scheduling module is used for detecting communication states so as to be switched to the spare PLC; the method comprises the following steps: detecting whether the communication between the station level integrated monitoring system network and the main PLC is interrupted through the redundancy scheduling module, and if so, then switching the spare PLC into the main PLC by the redundancy scheduling module. The invention is favorable for lowering the construction cost of the BAS system and reducing the difficulty in integrating a BAS subsystem by an ISCS, and can ensure the uninterrupted and undisturbed automatic switching operation of controlled equipment and modes when a fault appears in any single node.