Abstract: According to the characteristics of settlement on soft foundation and the limitations of commonly-used prediction methods, Weibull model is proposed to predict the roadbed settlement. The engineering significance of each parameter in this model is explicit by analyzing Weibull model. The influence of crucial parameters on the roadbed settlement is studied, and it shows the model has a good adaptability. For the commonly methods to solve the model are complexity, a simple method is proposed. The reliability of the proposed model and the practicability the relevant method are proved through case studies.