Low-temperature vacuum cold cabin collimation optical system with long working distance and large view field

The invention provides a long-working-distance and large-view-field low-temperature vacuum cold cabin collimation optical system, and belongs to the technical field of optics. An optical path part comprises an entrance pupil and aperture diaphragm, a primary mirror, a secondary mirror, a third mirror and an image plane; the primary mirror and the third mirror are concave aspherical mirrors, and the secondary mirror is a convex aspherical mirror; the image plane comprises a background focal plane, a test focal plane, a target focal plane and an interference focal plane, and the optical axis of the system is an optical axis; the optical axis of the secondary mirror coincides with the optical axis, the optical axis of the primary mirror and the optical axis of the third mirror have off-axis amount relative to the optical axis of the system, and the entrance pupil, the primary mirror, the secondary mirror, the third mirror and the image plane are sequentially arranged in the light propagation direction; the prima