A machining process of hollow cone prism is introduced in this paper.The first is to use optical cold working technology to process the substrate of three glasses, and carry out external rolling and coating treatment. Next, fix the three substrates using fixtures, and then apply a layer of adhesive to the bonding area. Finally, the core technical indicators of the hollow cone prism are monitored in real time by self-collimating parallel light tube, and the UV lamp is cured to control the molding. Practice has proved that the process can accurately control the dihedral angle of hollow cone prism, which is suitable for the cool processing of large-diameter hollow cones.