Abstract: The hydraulic fill in the reclaimed area is in a slurry state with high water contant of over 80% and large initial void ratio. The void ratio may greatly change during the reinforcement of vacuum preloading, and it is essentially different from that of normally consolidated soil. The conventional consolidation theory supposes the coefficient of permeability as constant, the calculated results of the consolidation of hydraulic deviate from those of the field tests. In order to improve the calculated results, laboratory tests are carried out. The relationship between the void ratio and the consolidation stress is obtained from the laboratory tests, and that between the permeability coefficient and the void ratio is proposed. At last, the relationship between the permeability coefficient and the consolidation stress is put forward. The Barron’s consolidation theory is improved by considering the coefficient of permeability to vary with time. A calculation is conducted to a vacuum preloading model test, the results are in accordance with the test data. It shows that the improved consolidation theory is suitable to the vacuum preloading of hydraulic fill.