The soft clay in the silted coastal plain area is a sedimentary complex of multiple lithology and lithofacies, with small failure strain and easy to be disturbed. The dynamic characteristics of this kind of soft clay have not been fully explored. Now, taking Nuoshan soft clay as an example, the indoor microcomputer-controlled dynamic triaxial test is carried out on the site, and the sine wave load is applied to the sample, and its dynamic characteristics are studied by changing the magnitude of dynamic stress, vibration times, and confining pressure. The results show that the dynamic modulus ratio increases and decreases exponentially with the dynamic shear strain r_dthan R_G. At the same dynamic shear strain level, the initial dynamic modulus increases with the consolidation pressure; Under the same dynamic stress amplitude, the maximum dynamic strain of soft clay will gradually increase with the increase of cyclic cycles and dynamic stress amplitude; When the vibration frequency increases, the dynamic strength of Lano sedimentary soil layer decreases correspondingly; And dynamic stress amplitude of soil layer σ_d with consolidation pressure σ_3e increases gradually; The dynamic internal friction angle decreases with the increase of the number of cycles. The research results can improve the understanding of complex sedimentary dynamic characteristics.