Abstract: In order to investigate the effect of microbially induced calcium carbonate precipitation (MICP) surface treatment on the disintegration resistance and scour resistance of granite residual soils and its microscopic control mechanism, the granite residual soils were treated by spraying and subjected to disintegration resistance tests and scour resistance model tests, combined with microscopic testing techniques such as scanning electron microscopy and particle size analysis. The results showed that after the sprayed MICP surface treatment, the microfine particles of granite residual soil were cemented into larger size agglomerates, the microstructure of the specimens was more dense, and a continuous cemented hard shell layer of calcium carbonate and soil particles with good water stability was formed on the surface of the specimens, which effectively improved the disintegration resistance and scouring resistance of granite residual soil.The results of the study can provide a reliable basis for the reinforcement of granite residual soil slopes.