Optical inspection of convex aspheric surfaces, especially off-axis convex aspheric surfaces, is always a difficult point in aspheric surface machining. A modified Hindle method is developed to solve the problem of machining inspection of convex aspheric optical elements, which is difficult to solve the deficiency of the classical Hindle method, such as the need of large aperture auxiliary spherical mirror and the presence of center occlusion. In this paper, a compensator set with special structure is designed for the detection of large diameter off-axis convex aspheric surfaces, and the processing and adjustment of compensators are analyzed, and the simulation optimization and tolerance analysis are carried out for the whole compensation detection system. Meanwhile, this design can be extended to the detection of larger diameter convex aspheric surfaces.