Abstract: Based on research of surface measurement method for large-diameter parabolic mirror, a new sub-aperture stitching measurement technology based on aberrationless theory was proposed. Firstly, the special method of sub-apertures'generation and the calculation form for sub-apertures'nominal motion path of this stitching program were analyzed. Secondly, a unified function between image plane coordinate system and the global coordinate system was established, together with coordinate transformation, the global coordinate of each sub-aperture data was solved. Finally, the full aperture surface was recovered by the objective function method. The simulation experiment was established for parabolic mirror, the stitching deviation of RMS is 0.001 4 . The experimental results show that this measurement method can achieve high precision measurement for large-diameter parabolic mirror.