Abstract: The spectral difference between the sensors, complexity of optical bench mechanics, as well as alignment between the optical axes and revolving axes in stabilized electro-optical sight system make the system integration accuracy hard to achieve. The fine tuning for the optical axes boresight was achieved by setting a spatial transfer reference with several sets of autocollimators and adopting a large-aperture optical axis adjustment device. Based on the synchronous accuracy requirement of optical axes and mechanical revolving axes, the scheme to assemble various parts and the impact of the assembly errors on system accuracy were determined. With an azimuth/elevation zenith instrument designed for this work, the orthogonality accuracy of revolving axes was satisfactorily obtained. The design specification and accuracy achieved with this technology cannot be met by traditional technique or ordinary adjustment devices.