There are direct relations between machining deformation and stress field of aerospace Al-based alloy thin-walled component. With stresses profile characteristics of the component after milling processing, building a mechanical model of stress-deformation analyses that effect mechanism of stress on deformation and then get the corresponding relationship between the both of deformation and stress. The process is as follows: the different degree stress-deformation distributions of the thin-walled component after milling is obtained by shot-peening treatment, and then the experimental values of the deformation and the calculated values of analytic functions under different technological conditions are compared and analyzed using layer removed method, XRD stress and three-coordinate shape measurement technology. The experimental results show that the deformation deflection is 3~12 μm between the experimental value and the calculation, and the deviation is within the deformation uncertainty. By this work mentioned above, the deformation function can achieve the predictive calculation and analysis of the deformation degree under the premise of the geometrical shape, the surface stress and the initial stress of the component. The research satisfies the demand for engineering application.