In order to improve the strength index of compacted loess in airport new town area of Xixian new area, the orthogonal test plan L9 (34) was designed to study the influence of moisture content, polypropylene fiber length and polypropylene fiber content on the compressive strength and deformation of compacted loess. Through the analysis of range and variance of unconfined compressive strength and deformation modulus of reinforced yellow soil, the influence of three factors was obtained At the same time, the blank control without fiber was set up. The results show that the improvement effect of the unconfined compressive strength of fiber reinforced soil is different under different water content, which is the highest at 19.5% water content, 2.1 times higher; the optimal mixing length of the unconfined compressive strength of polypropylene fiber reinforced loess is 12mm, the optimal mixing amount is 0.5%; the effect of the addition of polypropylene fiber on the deformation modulus is not significant, the change of the deformation modulus is controlled by the water content, and the polypropylene fiber is not significant When the dimension length is 12mm and the content is 0.3%, the deformation modulus is relatively optimal.