To explore loess soil of little area, the paper discussed the loess soil of Yangling soil field mixed with No. 42.5 cement of 4%, 5%, 6%, 7% and 8% in laboratory through improving the reliability and applicability of soil by cement . With the help of three kinds of conventional soil test methods such as liquid plastic limit test, compaction test and direct shear test, the paper studied the physical state index, optimal water content, maximum dry density and shear strength index of the loess soil improved by cement with five different mixing ratios, and then further analyzed the physical state index of improved soil.The result shows that the cement admixture can better improve the physical properties of loess soil. At the same time, the factors such as mixing ratio and age period of cement can greatly impact C value of strength index of loess soil while the cohesive force will increase with the enhance of cement blending ratio. The results have practical significance and reference value for the actual project of loess soil in yangling demonstration zone when the cement improved technology is applied.