In this paper, the degradation of Salix psammophila is used to make the polyurethane elastomer and study on the process involving changes in molecules with SPM. Compared with the pure polyurethane, it can be concluded that the polymerization of particles′ size, height and measurement have got bigger visibly. But the cured particles change nothing and retain the natural polymer’s linear permutation. And this polyurethane elastomer′s fracture profile is brittle