In order to obtain the whole lens′ precision surface information and reduce its errors transfer and accumulation, a new global optimization stitching algorithm based on weight coefficient is presented. The common region of the two neighborhood subaperture can reach the optimal match and the stitching error is minimized by using this algorithm. The multiapertures stitching simulation is carried out, and an actual experiment is carried to the flat lens of 150 mm. A new subaperture position method based on the image edge contour feature extraction is introduced and the error factors are analyzed for stitching. Both the simulation and the experiment results show that this global optimization stitching algorithm is good for reducing the transfer and accumulation error, which exist in the traditional method, and realizing the high precision subaperture stitching measurement.