Abstract: The soil improvement of high energy dynamic compaction displacement has been used to construct large storage tank in dredge soil ground, which contains sandy soil and muddy clay. The muddy clay in flowplastic is replaced by disturbed and sandy soil densified after the dredge soil is replaced by block stone. The index between stone columns obtained from detection and test in multigeotechnical ways, is very discreted. The results indicate that the distribution of soil properties is nonuniform in space, and it is difficult to estimate the settlement for composite ground. The Fuzzy cluster method is employed in this paper. After the soil index obtained from geological detection and test, their distribution is classified in a Fuzzy cluster. The soil classification of ground soil is obtained in differently distributed plane areas. Index after classified is ensured to be reasonable to some credit degree, and the settlement estimation of tank foundation is also made to conform to realistic cases.