Abstract: CDM (Consolidation decelerating ground treatment method) is a new ground treatment method which eliminates later ground consolidation settlement and controls the post-construction settlement by confining the pore pressure dissipation of the ground during the operation service period. CDM is refined by setting a deep horizontal anti-seepage layer and the research is based on it. Finite element method calculation shows that the post-construction settlement of ground treated by CDM decreases with the increase of depth of anti-seepage curtain, but no more decrease will occur when anti-seepage curtain is deep enough, while CDM with very shallow anti-seepage curtain results in larger ground post-construction settlement than natural ground. Comparisons of excess pore pressure distribution, vertical displacement field distribution, settlement time process curves and ground post-construction settlement controlling effect between a rigid pile and CDM are made by the finite element method, also, economy of the two methods is compared simply. CDM does can reduce ground post-construction settlement with a feasible depth of the anti-seepage curtain. CDM is better than the rigid pile on economy and technology with the treatment depth within a certain limit.