In order to satisfy requirements of displacement monitoring in drivetrain assemb lies of the vertical roller mill,this paper presents a new type of non-contact optical fiber grating displacement sen sor,which can provide the temperature compensation and improve the measureme nt accuracy.The theoretical analysis and experimental calibration are completed.The experimental results sho w the scale range of the sensor is 1-12mm,the resolution of displacement measu rement is 1μm,the repeatability err or is 2.6%,and the return error is 0.98% FS.Before the temperature compensation is carried out ,the impact of temperature on the displacement is 28.10pm/℃.After compensation,the impact becomes 0.88pm/℃. The sensor can be used to measure displacement of non-contact conditions in eng ineering.