:To address the contact nonlinearity issues in the structure of large-aperture refractive space telescope, finite element methods were employed to perform contact nonlinear analysis and opto-mechanical integrated analysis, ensuring the telescope′s normal imaging performance in a wide temperature range. Firstly, a centering turning process was employed in the structural design of large-aperture refractive space telescope, using tangential contact methods to reduce lens stress levels. Subsequently, contact nonlinear analysis was conducted to evaluate the deformation of large-aperture refractive space telescope under self-weight and thermal loads. The analysis examined the stress levels of the system under static conditions, such as gravity and temperature rise, as well as dynamic conditions, including random vibration and impact. Next, Zernike polynomial fitting was performed using Sigfit software, with the results imported into optical software for opto-mechanical integrated analysis. This step assessed the degradation of optical performance under variations in static mechanical conditions. The analysis results indicated that under both static and dynamic conditions, the maximum contact stress of the optical component is 1. 83×10 7 Pa, with a safety margin better than 0. 82. The deformation of optical components under load led to changes in optical system parameters, resulting in a reduction of approximately 2. 97% in modulation transfer function(MTF), which remains within acceptable optical tolerances. Finally, the complete system underwent machining, assembly, and testing. The test results showed that the wavefront aberration of large-aperture refractive space telescope system is 0. 123λ(λ = 632. 8 nm), and field imaging test produced clear images, meeting the requirements for space-to-ground observation. This provides valuable references and guidance for the further optimization design and development of large-aperture refractive space telescope.