Settlement deformation monitoring and prediction is the important aspects of building.However，because of finite cost and damage of monitoring points，settlement data often have incomplete or irregular time intervals，leading to worse predictions.In this paper，the limitation of the grey model is improved and validated with the settlement data of the deep soft clay layer of a cruise terminal project.The results show that：1) the R2 of both the improved and the common grey models are greater than 0.9，and the average error is less than 15%.2) the middle and latter part of the prediction curve of the improved grey model is closer to the settlement monitoring data than that of the common grey model.The accuracy of the improved model is higher，which proves the superiority of the new model.3) S17 has the worst accuracy，which may attribute to little settlement data and larger initial time interval.It is recommended that settlement monitoring should be as frequent and complete as possible within the cost range.