Soil condition is a major impact factor on the strength of cemented soil. In order to study the relationship between the soil conditions and the strength of cemented soil in deep mixing column under the circumstance of thick soft clay in the Nansha area, the uniaxial and unconfined compressive strength tests were carried out, from which stress-strain curves of the cemented soil and strength-depth curves of column body were obtained under three different soil conditions. Analyzing these curves, conclusions can be made that the strength of different parts of cement soil from deep mixing pile varies greatly in the Nansha area. Among the samples, the cement mixed with silty clay has the highest strength, while the lowest one is the cement mixed with mud. Besides the above results, compressive strength values(fcu)of cement soil is determined, which can be of great significance to calculate the bearing capacity of deep mixing piles.