The paper selected remodeling gravelly clay soil as test sample,and used the indoor dynamic triaxial testing system to research the modulus regular of soil under cyclic load weakening, and considered the fit of settlement formula after tunnel construction under multiple factors. Experiment showed that accumulated strain and cumulative pore pressure increases with the increase of confining pressure and dynamic stress ratio and reaches a steady after vibrating 10,000 times, while the modulus weakening amplitude shows the opposite rule. If the pore pressure is cumulated at different excitation frequencies,the cumulative strain decreases with the increase of frequency, the weakening amplitude of modulus decreases with the increase of frequency. On the basis of previous research,the paper further considered the effect of excitation frequency on accumulative strain,and fitted the cumulative pore pressure formula to get relative parameter. The result can provide a valuable reference for the prediction of dynamic characteristics of soil frail shield and the settlement of gravel cohesive soil after tunnel construction.