Abstract: To realize the resource utilization of dredged silt-solidified soil and to explore its dynamic characteristics as the railway subgrade fill, the triaxial tests on the dredging project of Daqinghe River in Tai'an, Shandong Province are carried out, and the characteristics of dynamic stress-dynamic strain relationship, dynamic shear modulus and damping ratio under different ratios are analyzed. The results show that the trend of dynamic stress-strain relationship curve under different ratios is generally the same, and the double-mixture fly ash produces greater shear strain than the single cement sample under the same conditions. The change trend of the damping ratio under each ratio is basically the same. The damping ratio first decreases and then significantly increases with the increasing kinetic shear strain. The damping ratio of the final single sample is stable at about 30%, the double-mixture test sample is stable at 10%~20%. The fitted logarithmic curve of the cumulative plastic deformation of soil samples with the vibration number is obtained and evaluated, and it is obtained that the cumulative plastic strain of each sample meets the requirements of dynamic stability. It may provide some reference value for the feasibility of silt-solidified soil as the railway subgrade.