Device for calibrating parallelism of optical axis of multi-axis optical system, and calibration method thereof

The invention discloses a device for calibrating parallelism of optical axes of a multi-axis optical system, and a calibration method thereof. The device comprises a high precision autocollimation theodolite, a planar mirror, a to-be-calibrated multi-axis optical system, a pedestal, a cross target plate and a rotary platform. The multi-axis optical system and the planar mirror are both disposed on the pedestal. The pedestal is placed on the rotary platform. The cross target plate is fixed in a position 1000 times of the longest lens focal length away from the front end of the optical system. The autocollimation theodolite is disposed behind the planar mirror and is used for aiming. Through rotation of the rotary platform many times, the direction values of the planar mirror, which are measured by aiming of the autocollimation theodolite, are obtained. The directions of optical axes can be known by calculating the direction values measured many times. The difficulties in manufacturing and installing detection equipment can be reduced, less requirements of places are needed, the measuring operation is convenient, high applicability is exhibited, and installation errors of the planar mirror are eliminated. The device is suitable for measuring or calibrating parallelism of optical axes of a multi-axis optical system and a multispectral multi-axis optical system.