Abstract: Objective: Targeting the possible risks in the main/standby dualsystem status switchover of rail transit signaling control system redundancy structure, a new hardware judgment method to avoid those risks is proposed. Method: Rail transit signaling control system often adopts double 2 out of 2 method and dualsystem hot standby redundancy structure. The system consists of main and standby two systems that perform the same function, each has three working status of host, synchronization or offline, and they are not allowed to be in host status at the same time. Control and switchover of the 3 working status depend on the working status of the system itself and the other one. At present, the judgment mechanism of system working status mainly includes communication judgment and hardware judgment. For communication decision, there is a risk of both systems in host control status simultaneously during communication faults. Thus the hardware judgment method with working relays is put forward, meaning that relays are used to identify and control the working status of the main and standby dualsystem to avoid the above risk. Main and standby systems set up a working relay respectively to reflect the working status of the corresponding system by relay hardware joint condition, for which the design theory, decision principle, decision implementation flow and application environment are proposed. The technical advantage of hardware judgment over communication judgment is analyzed. Result & Conclusion: By collecting working relay position, the working status of corresponding systems under the railway signaling control system is reflected. Main advantages are as follows: (1) independent of the communication status between main and standby systems, status information loss caused by communication problem is solved; (2) whether system is turned on or communication between systems is normal, both main and standby systems can identify the working status of the other one by collecting working relay joint condition, thus control working status of itself accurately; (3) relay response speed is evidently faster than communication process response speed, and once system working status switches, working relays of both main and standby systems can act instantaneously to inform the other one of their working status; (4) relay has intrinsic failsafety feature, meaning that if the working relay fails, system will be turned to offline status as soon as possible; (5) identifying and controlling system working status through relays, the software processing logic becomes simple and the maintenance personnel can identify system working status intuitively.