In the large area enclosed land reclamation project,with the development of construction technology,the use of dredged sludge as filler gets a lot of applications.But the corresponding settlement calculation can not meet the actual needs,and the estimated settlement amount only by virtue of experience.Using the two-phase of saturated soil’s water and soil properties,we calculate further the amount of soil subsidence and obtain the settlement formula by calculating the change in the moisture content of the soil before and after reinforcement,which is validated by actual project’s settlement monitoring data.