Abstract: The load in the process of construction is mostly a linear or approximately linear loading level; the settlement time curve has the characteristics of "S" type. The paper mainly studied the application of the WEIBULL curve and improved POISSON curve model in the settlement regularity and prediction of the whole process of CFG the long-short-pile composite foundation, got the optimization iteration method for solving the model parameters, combined with Seoul garden engineering project application, the result indicates that the two models have high accuracy for the whole process of composite foundation settlement fitting, which can meet the needs of the engineering application, improved the POISSON model is slightly better than the WEIBULL model.