In order to realize wavefront reconstruction over full aperture of aspheric surface at the beginning of polishing, a novel method combing coordinate measuring machine (CMM) and digital interferometer was proposed. The main part of surface is able to be measured by interferometer. The rest part, wavefront of which cannot be recovered by interferometer, can be measured by CMM. By combing the data from CMM and interferometer, the error of surface can be reconstructed and the wavefront over full aperture can be obtained ultimately. In the testing, wavefront of an off-axis aspheric surface with 540 mm diameter was successfully reconstructed over full aperture during the process from grinding to polishing. The availability of the method for wavefront reconstruction of aspheric surface was proved by the results.