The thickness of the thin shell used in the large aperture adaptive mirrors is usually less than 2mm, in contrast the shell’s diameter could be larger than several hundred millimeters, so that the shell’s stiffness could be low enough to adapt the high frequency deformation. However the shell could very easily be out of shape during the process when the pads were glued onto the mirror, some analysis based on the experiment would be presented in this paper, and force introduced by the glue process could be extracted by the method, so the result could be used during the polishing process to eliminate the influence of the bonding process on the shell.