Abstract: The average of vacuum pressure using the equivalent circle of single well foundation, instead of the average of vacuum pressure of mul ti-boreholes, was applied to specify the method to calculate foundation settlement under k_0 consolidation condition. Founding on the advanced method considering soil lateral displacement to calculate foundation settlement, the paper took new consideration and analysis with the modify coefficient in volumetric strain, and specified the concepts upon the coefficient of average volume stress, also firmly believed that the consolidation settlement considering soil lateral displacement should modify formula by applying the method ofaverage volume strain. Proceeding from finite element analysis, this paper made a comparison between the result of theory analysis, FEM calculation and surveillance. And the result was reasonable and reliable. It was more Reasonable and convenient to apply the method to forecast foundation settlement and it can be a reference to the generalization and application of the designs of vacuum preloading method.