Rainfall erosion seriously threatens the stability of soil slopes and even induces instability and failure. In this study, jute fiber and microbial induced calcium carbonate precipitation (MICP) technology were combined to carry out ecological reinforcement of loess slope. Simulated rainfall test was used to analyze the improvement degree and influencing factors of slope erosion resistance. Scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDS) were used to analyze the mechanism of mitigating rainfall erosion on loess slope from a micro perspective, and to explore the feasible means of mitigating rainfall erosion on loess slope. The results show that: (1) The addition of jute fiber can help to improve the rainfall erosion resistance of microbial mineralized loess, especially the medium and high content of medium and long size fiber. (2) The fiber reinforced loess treated by biomineralization can significantly resist the erosion of weak rainfall (6mm/h) and short-term erosion heavy rainfall (45mm/h). Under heavy rainfall conditions, the corrosion resistance increases with the increase of fiber content, but the increase range gradually decreased, and the highest corrosion resistance increased to 64.2%.(3) With the increase of fiber length and fiber content, the thickness difference between C2L5 and C8L25can reach 2.86 times.(4) There are two cementation modes in the surface layer of fiber-reinforced microbial mineralized loess: 1) the “intergranular filling” mode formed by the precipitation of calcium carbonate crystals in intergranular pores; 2) The “wrapped cementation” mode of calcium carbonate is formed by wrapping soil particles with fiber connection. The research results have practical guiding significance for the effective implementation of slope rainfall erosion prevention and control measures in the loess hilly and gully region.