Abstract: In order to study the factors affecting the CBR value of the fiber-reinforced loess and the mechanism of the fiber-reinforced soil, chopped basalt fiber was used as the reinforcement material, and the CBR test was performed by changing the moisture content, fiber length, fiber content, compaction times and soaking time. The experiment explored the influence of initial moisture content, fiber parameters and test methods on the local shear strength of the reinforced soil. The results show that the CBR value of the fiber-reinforced loess has a tendency of increasing first and then decreasing with increasing moisture content. There is an "optimal moisture content for construction" and it is about 1% greater than the optimal moisture content of the compaction test. The CBR value of the reinforced soil is higher than the CBR value of loess. It is found that the fiber length of 20 mm and the fiber content of 0.4% are the optimal ratio. The compaction times increase from 30 to 98, the CBR value increases by 273%, the CBR value increases by 327% after the fiber is added. Reinforcement makes the soil local shear strength more effective by increasing the compaction work. The water immersion has a greater effect on the CBR value of the sample and the soaking time has less effect on it. The sensitivity of the sample to the soaking time is further reduced by the addition of fibers. The strength is reduced by 54% after 2 days of soaking, and the strength is reduced by 58% after 4 days of soaking.