应用双剪屈服准则推导了不同尺寸和边界约束条件下 ,水泥土圆柱体试件抗压强度的理论计算公式 ,理论分析表明水泥土抗压强度与圆柱体高度和直径比有关 ,而且与表面是否抹油有关 ,理论分析结论得到了试验结果的验证。根据理论分析与实测结果 ,对工程中水泥粉喷桩钻芯试件尺寸提出了建议 The theoretical calculation formula of the compressive strength of cement-soil cylinder specimen under different constraints and boundary conditions is deduced by using the double-shear yield criterion. The theoretical analysis shows that the compressive strength of cement-soil is related to the height and diameter ratio of the cylinder, Oil-wiping, theoretical analysis concluded that the test results verify. According to the theoretical analysis and the measured results, the size of the cement powder injection pile core sample in the project is proposed