The collimating optical system represents a critical component of optical testing devices, with stringent technical specifications required in the field of laser beam quality measurement and calibration. A high-precision assembly and adjustment method for an off-axis hyperbolic optical system is proposed. The applicability of the compensation method and the aberration-free point method in verifying the conical coefficient k of hyperbolic mirrors is analyzed. Based on the parameters of the primary and secondary mirrors, these methods are selected for surface shape testing to achieve precise assembly of the mirrors. Considering the structural characteristics of the off-axis R-C system, mechanical end faces and a horizontal plane are utilized as reference points for alignment. This approach ensures parallelism between the optical axis of the interferometer, the normal of the flat mirror, and the optical axis of the primary mirror, establishing a proper relationship with the adjustment references. The correlation between the misalignment of the secondary mirror and the resulting wavefront aberration of the system is examined. Computer-aided adjustment facilitates six degrees of freedom in the alignment of the secondary mirror, enabling rapid convergence of the wavefront aberration. After adjustment, the system achieves a root mean square RMS wavefront aberration better than 0.0245λ@632.8nm, satisfying the specified design criteria.