Based on dual-differential comparing principle, an experimental system of optical fiber F-P interferometric micro-displacement measurement is introduced. It is capable of achieving the absolute displacement measurement, and wavelet transforms is adopted as theory fundament to extract the optical F-P interferometric characteristic signal and remove the noise, so its resolution can reach 0.01μm in the dynamic range of 0~1mm. Based on dual-differential contrast principle, an experimental system of optical fiber FP interferometric micro-displacement measurement is introduced. It is capable of achieving the absolute displacement measurement, and wavelet transforms is taken as theory fundament to extract the optical FP interferometric characteristic signal and remove the noise, so its resolution can reach 0.01μm in the dynamic range of 0 ~ 1mm.