The quality of optical machine installation in a 1 000 mm aperture reflector directly influences the imaging characteristics of the optical system of a telescope. In order to improve the imaging quality of a large-aperture photoelectric tracking system, the installation and adjustment technology of the reflector was investigated. First, the errors that affect the precision of the principal mirror were distributed. Second, a typical method was adopted to perform a detailed installation and adjustment investigation of the principal mirror with an aperture of 800 mm, and the reflection mirror shape accuracy was measured in real-time, in combination with the specific form of the reflector support structure. Finally, this paper included a comprehensive analysis of the source of installation and adjustment errors and proposed a high-precision method that integrates processing, testing, and installation. The method adopted resulted in an RMS value of λ/40 for the modified profile precision waveform aberration after installation, and significantly improved the efficiency and quality of the installation and adjustment.