Abstract: In order to systematically research the factors affecting coupling efficiency, the coupling model of semiconductor laser and single-mode fiber was established and an automatic coupling platform was built by means of simulation and experiment. Theoretical analysis and experimental verification were carried out, and the relationship between coupling efficiency of the model and displacement sensitivity of each direction and the relationship between coupling efficiency and tolerance of each direction in the actual coupling process were obtained. The results show that, coupling efficiency is most sensitive to horizontal displacement, followed by angular rotation and longitudinal displacement. The maximum coupling efficiency of simulation and experiment is 64.29% and 51.46% respectively. The error of simulation and experiment is within a reasonable range, thus the results are highly credible. The results are helpful to improve the packaging coupling efficiency of practical photoelectric devices.