In order to understand the influence of fiber on the mechanical properties of cement soil, the unconfined compression test and fatigue test of cement soil and fiber reinforced cement soil are carried out. The results show that the compressive strength of cement soil can be improved slightly by adding fiber. Compared with plain cement soil, the strain of fiber cement soil increases obviously at the stress peak point; and its residual strength after failure also increases. The addition of fiber improves the ductility of the cement soil, reduces the crack development and improves its mechanical properties. After the fiber is added, the antifatigue ability of cement soil is significantly increased. The degree of the improvement of cement soil fatigue resistance is much greater than that of unconfined strength of cement soil. The relationship between stress level and fatigue life of cement soil is single logarithm linear. The cement soil is characterized by low stress rupture under cyclic loading.