Abstract: The engineering has great practical significance for the prediction of post-construction settlement,and the secondary compression coefficient is the key parameter for the prediction of post-construction settlement.It is a difficult problem to determine the second compression coefficient of dredged coral sand by laboratory tests with undisturbed soil samples.In this paper,a method is presented for estimating the secondary compression coefficient of coral sand based on the comparison and inversion of the subsidence of vibratory compaction and a calculation example is given.The method infers the secondary compression coefficient of coral sand by inquiring the historical filling time of the old dredger filling site,comparing the surface settlement of the new dredger filling test area and the old dredger filling test area in the course of the ground treatment test of vibratory compaction.At the same time,the factors are analyzed of affecting the inversion results.