Recently, the vacuum preloading method has been used as a popular improvement method in Vietnam. In this paper, the improvement work by the vacuum consolidation at the new urban of Thu Thiem is presented and analyzed. The project is located in the Ho Chi Minh City of Viet Nam, which has a thick layer of soft clay. The behaviors of vacuum-induced consolidation process have been analyzed by the finite element method via the Geo-Studio Suite software. The simulated results were close to the monitored settlement, lateral displacement, and excess pore water pressure. The further analysis of settlement showed the degree of consolidation by vacuum pumping as compared with fill preloading method. Moreover, the effects of the sand seem layer on the vacuum consolidation process were studied. From the studied results, the conclusions and the proposals are presented for the soft ground improvements by the vacuum preloading method at the new urban of Thu Thiem, Ho Chi Minh City, Viet Nam.