In order to improve the problems of wellbore instability and lost circulation caused by fractured strata in the southern margin of Junggar Basin，a cementing strong plugging and anti-collapse agent XZ-OSD was developed by imitating the multilayer composite structure of shell and combining the bionic strong plugging theory. The structure of XZ-OSD was characterized by SEM and IR，its thermal stability，fluid loss reduction effect and plugging property were evaluated，and the plugging mechanism was analyzed. The results showed that the spherical particle size of XZ-OSD was 50—200 nm. XZ-OSD had good thermal stability，and the decomposition temperature was 250℃. XZ-OSD had a significant fluid loss reduction effect. When only 1% XZ-OSD was added to the base slurry，the API fluid loss of oil-based drilling fluid was reduced by 72.22%，and the fluid loss at 150℃ high temperature and high pressure was reduced by 81.43%. XZ-OSD had a significant effect in protecting oil and gas formation. After 1% XZ-OSD was added to the plugging slurry，the forward plugging rate and reverse plugging rate of the core were increased by 2.89 times and 0.4 times，respectively. XZ-OSD had a good plugging effect at hightemperature. When 6% XZ-OSD was added to the plugging slurry，the fluid loss after heating at 180℃ for 16 h was only 2 mL. After entering the formation，XZ-OSD could enter pores and cracks of different sizes，plug the pores and cracks through the bridge plug and bridging. Furthermore，XZ-OSD expanded in contact with oil，the pressure-bearing capacity of leakage layer was enhanced through the expansion property and the cementing ability，thereby improving the stability of wellbore，and avoiding the occurrence of complicated down-hole accidents such as lost circulation.