The invention discloses a relay protection system for a 10-kilovolt two-stage switching station. The relay protection system comprises relay protection devices arranged at two ends of a protected power line of the two-stage switching station, wherein a control unit is connected with the relay protection devices at the two ends of the protected power line; each relay protection device comprises a plurality of acquisition units which are connected with the protected power line and are used for acquiring the electrical quantity of the protected power line and a relay unit for executing switch-on and switch-off operations; the acquisition units and the relay units are respectively connected with the control unit; the control unit is used for receiving an electrical quantity parameter acquired by the acquisition units and processing the acquired electrical quantity parameter to judge whether to perform relay protection on the protected power line. The relay protection system can realize communication between every two adjacent relay protection devices and is convenient for checking whether fault is caused inside or outside the protected power line.