In order to acquire better forecast results for settlements of dykes with fabric form sand, a fractional-order grey model is presented based on the grey model. The program was established using MATLAB to change the differential-order derivative into a fractional-order one. This model was used to predict the settlement of dykes with fabric form sand. Comparative analysis of the grey Verhulst model, residual GM model, and proposed model was performed. The results show that the predicted results of the fractional-order grey model are more accurate, and the fractional-order grey model not only has the reliable previous forecast effect of the GM(1, 1)model, but also the reliable later forecast effect of the Grey Verhulst model. Moreover, the long-term forecast results of the fractional-order grey model show a higher degree of stability than those of the GM model.