The misalignment between the azimuth axis of telescope and rotation axis of earth induces object-side field rotation, and the relative motion of folding mirrors in the Coude optical path induces image-side field rotation. The misalignment and rotation both occur during the process of the alt-azimuth telescope tracking observation. A K-mirror can compensate for the rotation but is inappropriate in high-precision polarimetry owing to its higher instrumental polarization. By optimizing the design, the depolarized derotator comprising five mirrors can reduce instrumental polarization while eliminating field rotation. However, its irregular structural design leads to a more complex alignment process. Herein, an auto-collimation dual optical path alignment scheme was designed for the depolarized derotator. The influence of mirror position error and optical axis deviation on the alignment process was analyzed using MATLAB simulation. The alignment and polarization detection for the depolarized derotator were conducted in the lab. Results indicated that the alignment error of the depolarized derotator was within 15 arcsec, and its instrumental polarization was significantly lower than that of the K-mirror.