In winter, hydraulic concrete is often under the synergistic destruction of the freeze-thawcycle, dry-wet alternation, and salt erosion. The special climate in cold and arid areas hasadverse effects on the safe operation and economic benefits of hydraulic buildings. Thedurability of polypropylene fiber-modified concrete under multiple working conditions wasstudied. Combined with the FOTP-GM (1,1) model, damage prediction of modified concreteunder different working conditions was carried out. The results show that a certain amount ofpolypropylene fiber significantly increased the corrosion resistance of specimens. The fittingdegree between the measured sequence and the model increased with increasing order ‘h’ ofthe time power term. Under different working conditions, the time power term correspondingto the optimal model structure was different. The correlation coefficient R2 between theestablished prediction model and the original sequence was above 0.9. Through erroranalysis, it was proved that the FOTP-GM (1,1) model can effectively predict the number ofcycles when the concrete reaches the failure standard. The optimal model structure can beused in practical engineering to establish a prediction model to calculate the safe 0service lifeof engineering structures.