The resonance column test of sericite schist residual soil widely distributed along Dalin Railway was carried out to study the influence of different water content, dry density and consolidation confining pressure on dynamic shear modulus Gd and damping ratio D in the range of small strain (10^-6<γd<10^-4). The test results show that water content has a greater influence on dynamic shear modulus and damping ratio, followed by dry density and consolidation confining pressure. Gd and D increase nonlinearly with the increase of water content, and there is a critical water content that makes Gd reach the maximum value, and then Gd gradually decreases with the increase of water content; under the condition of high confining pressure and high water content, the relationship curves of D ~ γd tend to coincide. Under the same dynamic shear strain amplitude, dry density increases, Gd increases and D decreases. Under different consolidation confining pressures, Gd decreases with the increase of dynamic shear strain γd. the effect of consolidation confining pressure on D is not obvious, but when γd is the same, D tends to decrease with the increase of consolidation confining pressure.