Based on the project of Shenzhen—Zhongshan linking with deep cement mixing method (DCM) foundation treatment,we carry out the indoor mix ratio test of the marine soft soil layer,and analyze the effects on the strength characteristics of cement soil,including the soil layer properties,cement content,age,cement soil moisture content,as well as the cement soil density.The test results show that the cement hardening effect of the marine soft soil layer in the engineering area is significant.The strength of cement soil in 56-day age is above 2.0 MPa,and the cement content suggested would be higher than 260 kg/m3 in DCM treatment.The moisture content and density of cement soil basically remain unchanged during the hydration reaction,which mainly depends on the physical properties of the undisturbed soil and causes the cement soil strength difference.Furthermore,based on the test results,we establish a cement soil strength prediction formula for each layer of soil,and verify the validity of the strength prediction formula by comparing the measured and predicted strengths of the cement soil strength on the south side of the project site.