Railway departments in various countries are looking for a technology with convenient operation, low price, excellent measurement performance and stability for spatial position measurement of railway track. Therefore, we design an optic-electronics stereo system based on the principle of optical stereo measurement. The experimental verification in the real railway environment shows that the performance of the system is that the longitudinal relative displacement measurement range is 200—10 000 mm, the relative distance measurement range is 4 500 mm and the measured root mean square (RMS) error value is less than 1.1 mm in the whole process. Therefore, it meets the relevant needs of the Russian Ministry of railways.