China is the country with high incidence of high myopia in the world. High myopia can cause severe vision impairment. So far, there is no effective treatment for high myopia in clinic. Scleral collagen cross-linking surgery has been proven to be effective in preventing animal eye axial elongation in vitro and in vivo. However, the influence of posterior scleral collagen cross-linking on the deformation of the whole eyeball is still unclear. In this study, finite element simulation were used to analyze the changes of eyeball shape and the position of light casting on the retina after posterior sclera cross-linking, and the mathematical algorithm was written to verify their similarity. The results showed that the shape of the whole eyeball was still very similar before and after cross-linking, and the diopter of the eyeball after cross-linking had little change, which had almost no effect on the position of light projection on the retina. Our results indicate that posterior sclera cross-linking wouldn’t lead to distortion to the optometry, that is, the increase of elastic modulus in local scleral tissue after cross-linking wouldn’t cause new problem of optometry and vision.