The lobster eye optics is the key technology that could achieve high energy ray imaging with a large field of view. The focusing principle of the lobster lens was explained in the viewpoint of optical imaging. The improved lobster eye lens prototype which was based on the Schmidt geometry was made, and the testing of this system within visible light was finished. The reflection working surfaces of this lobster lens prototype were made of polished aluminum plates with 300 μm thickness. And the reflectors were arranged into fan shape; the whole lobster eye lens prototype was completely spherical symmetric structure. The angle 27.6′ between reflectors were generated by the special wedge plates. The focal length of the prototype is 65 mm and center angle is 17.48°×17.48°. The imaging ability of the system on every direction had much the same effect. It can meet the required of the large field detection task in space.