To reduce the slope collapse and soil erosion under the action of rainfall erosion in desertification areas, the self-developed nano silicon-based sand-fixation material (Nano-Silicon/

Polymer Composites, NSPC) is proposed to protect the sandy slope surface of the Yarlung Zangbo River Valley in Xizang. In view of the unclear effect of NSPC sand-fixing material on strengthening sand body, based on infrared spectrum, viscosity test, contact test and simulated sandy slope rainfall erosion test, the mechanism of NSPC sand-fixation material to strengthen the sandy slope is discussed, and the anti-erosion ability of the NSPC sand-fixation material under the rainfall is studied. The results show that the NSPC sand-fixation material and sand particles cross and intertwine with each other through polymerization and cementation to form a 3D network structure, so as to achieve the purpose of strengthening the sandy body. The rheological properties of the NSPC sand-fixation material belongs to Bingham fluid in the first 1 h, and gradually changes to Newton fluid in the later period. The surface tension of the NSPC sand-fixation material is 60.31 mN/m, the contact angle with sandy body is 48.6°, and the adhesion force is 0.040 N/m, therefor it has strong infiltration ability. The reinforcement layer formed on the sandy slope surface has strong blocking effect on rainwater erosion, and the reinforcement layer also has water retention ability. This study provides test support for the application and promotion of the NSPC sand-fixation material in sand fixation and protection projects in desertification areas.