Abstract: Zernike polynomial is an important data transmission tool for thermal/mechanical/optical integrated analysis, which can be used to implement data transmission between optical, structural and thermal analysis program effectively. However, for many optical surfaces, finite element analysis(FEA) is unable to accurately fit their surface distortion and the various aberrations generated by such distortions because they could not meet the orthogonality condition required by Zernike polynomial, such as a mirror with a central hole. The factors effecting orthogonality of Zernike polynomial were discussed. A new method for importing FEA deformation data of optical surface into optical analysis software, interferogram interpolation, was presented. This method transforms the surface distortion data into the interferogram data accurately after removing the displacement of the mirror body and directly implements them into the optical software.