Array microstructure optical elements are widely used in various beam homogenization occasions, but conventional processing methods cannot meet the accuracy requirements of large-sagittal convex cylindrical arrays. In this paper, the ultra-precision turning forming method is used to analyze the main factors affecting diamond turning, the sequential search method and the binary search method are designed to find the turning track, and the advantages and disadvantages of the two methods are compared. Furthermore, the binary search method is successfully found by combining the Matlab software turning trajectory and the numerical control program. As proof-of-concept demonstrations, turning experiments are carried on an ultra-precision lathe, and a large-vector high-array microstructure with a surface profile error of 135 nm is obtained. It proves that the force binary search method can accurately obtain the turning trajectory, and this method can be applied to both spherical and aspherical contours, showing important engineering application value.