In this paper, the morphology characteristic of tensile test fracture of polysulfide sealants immersed in oil for different time was observed through scanning electron microscopy. Combined with the performance data of tensile test, the effect of oil immersion time on the properties and fracture behavior of sealant was studied. The results show that the fracture of polysulfide sealants includes rough region and flat region. After being immersed in oil, the area of rough region diminishes and the roughness of fracture decreases. Within 168h, oil immersion time has little effect on the tensile strength and elongation of sealants.