Assembling and adjusting device and method for off-axis beam shrinking optical system

The invention provides an assembling and adjusting device and method for an off-axis beam shrinking optical system. The device comprises a ZYGO interferometer, an off-axis beam shrinking assembling and adjusting subsystem, an off-axis beam shrinking optical system, an azimuth pitching table and a reference reflector, wherein the off-axis beam shrinking optical system comprises an off-axis secondary mirror chamber, an off-axis secondary mirror, a main frame, an off-axis primary mirror and an off-axis primary mirror chamber, the main frame is fixed on the azimuth pitching table, the off-axis beam shrinking assembling and adjusting subsystem comprises a side surface tool and a front surface tool, the side surface tool drives the front surface tool to do translational motion, the front surface tool drives the off-axis secondary mirror to do rotation, pitching motion and translational motion, the ZYGO interferometer is located in front of the off-axis primary mirror, the reference reflector is located in front of