In recent years, cement-soil has been widely used in soil reinforcement projects, and its strength is closely related to the reinforcement effect. In order to study the effect of the adding amount of bentonite and fly ash on the performance of cement-soil, the basic mechanical properties of 25 groups of cement-soil with different adding amount of bentonite and fly ash were tested. Through the compressive strength test, it was found that when the blending amount of fly ash and bentonite was 40% and 11% respectively, the 28d compressive strength of cement soil was the largest at 7.30MPa; when the blending amount of fly ash and bentonite was 20% and 7%, the 90d compressive strength of cement-soil was the highest at 7.19MPa. Through the indoor direct shear test, it was found that when the fly ash and bentonite content was 20% and 11% respectively, the 28d cement-soil shear strength parameter, e.g. cohesion c, was the largest at 1144.8kPa; when fly ash and bentonite was added with the amount of 30% and 5% respectively, the cohesive force c of the 90d cement soil shear strength parameter was the largest at 1753.71kPa. The research results can provide reference for the on-site preparation of cement-soil with fly ash and bentonite in Wuhan area.