Elastic deformation has always been a key factor restricting the machining quality in thin walled machining. In order to solve this problem， a method for the prediction and compensation of elastic deformation is investigated in this study. Firstly， based on the finite element method， a layered milling model is built for the straight micro-thin wall with different thicknesses. The deformation law of the thin wall along the direction of height and length is studied. A thin wall deformation model with the cantilever beam method is establishedby considering the effect of material removal on the stiffness of the thinwall. Secondly， a single degree of freedom cutting force measurement and real-time cutting parameter compensation device is developed. The thin wall deformation is estimated based on the cutting force and deformation model measured in real-time during the thin wall cutting process. The deformation prediction is used for the compensation value to compensate for the radial cutting parameters in real-time. At last， a comparative experiment is conducted. The results show that the average relative error of the thin wall decreases from 6.86% to 2.19% after the radial cutting parameter compensation， which verifies the model reliability and the effectiveness of the compensation device.