The stability monitoring of steel cushion beam during operation and maintenance of railway tunnel and the real-time accurate feedback of monitoring data are of great significance to the construction safety of existing operation railway line. Hence, the displacement data of steel cushion beam of a railway tunnel is monitored by accurate grating displacement meter with grating demodulator, GPRS transfer module and static leveling instrument with acquisition software; the monitoring data are analyzed by calculation software in real-time to guarantee the stability of the steel cushion beam; the track coordinates on the steel cushion beam are monitored and compared by measuring robot; and the monitoring data are analyzed to verify its accuracy. A set of monitoring methods for the stability of steel cushion beams during railway tunnel operation and maintenance is put forward, which realizes real-time feedback of the monitoring data and guarantees the safety of operation and maintenance of railway tunnel.