Optic nerve injury is one of the primary causes of vision loss, so accurately assessing the extent of optic nerve fiber damage is critically important for effective treatment and rehabilitation. In this manuscript, the optic nerves of pig eyes are imaged before and after injuries using a swept-source polarization-sensitive optical coherence tomography system built with polarization-maintaining fiber components. The microstructure and birefringence characteristics of the optic nerve are observed and reflected through Stokes parameters Q, U, and V, representing the polarization state of the detection light. It was found that the V cross-sectional image has good characterization ability for the birefringence characteristics of the optic nerve. The high birefringence region and the non-birefringence or low birefringence region corresponding to the V cross-sectional image were segmented by the threshold method. The evolution of the average area and the average height of the high birefringence region in the cross-sectional image of V can reflect the damage, repair, and erosion of the optic nerve, which indicates that polarization-sensitive optical coherence tomography has a good perceptual ability for changes before and after optic nerve injury and is crucial for evaluating the degree of optic nerve injury, which can provide important reference data for early diagnosis and treatment of optic nerve injury.