To reach the requirement of the high precision displacement measurement in Taiji program, it is necessary to reject the optical path noises caused by the structure deformation. Different from the spatial optical path establishment, we present a methodology to monitor the micro-deformation based on the all-fiber-optic sensor, which can be pasted to the surface of the target components. In this paper, the all-fiber-optic sensor is applied to reflect the deformation of the cantilever beam as an example. The experimental results reveal that the sensing scheme adequately aligns with the theoretical predictions with the acceptable tolerance for error, and the deformation measurement error of the sensor is reduced from 240 nm to 17.2 nm through the noise suppression scheme. It validates the feasibility of the contact and the high precision micro-deformation measurement and turns out to be a promising candidate to monitor the surface micro-deformation of the target components, such as the optical platform, the telescope framework and the satellite structure in the future Taiji program.