Abstract: The mucky soil embankment settlement is predicted by commonly used fitting curves, such as the hyperbolic curve, three point curve, S type curve, and the accuracy of the 3 curves is analyzed. Considering the advantages and disadvantages of a single method, the combination forecast model is established by using the optimal weighting, and the optimal weighted coefficient is determined by object function of minimum sum of squared error and maximum effective degree.  The comparison results show that, among single prediction, the three point method has the highest prediction accuracy, and the optimal combined forecasting model has higher accuracy than single prediction model, and its reliability is better.