In order to examine the influences of drying-wetting cycle on stability of cement-improved argillite-slate coarse-grained soil under dynamic loading，large-scale dynamic triaxial compression test on the soil at the standard curing age of 28 days was carried out.The mechanical characteristics parameters of improved soil，such as the change of dynamic elastic modulus，damping ratio and dynamic stress compressive strength with the drying-wetting cycles were studied by the tests.The influences of confining pressure on the dynamic properties under drying-wetting cycles were analyzed，and the influence mechanism of drying-wetting cycle was also discussed.The results indicate that：1) Both the maximum dynamic elastic modulus and dynamic compressive strength decay with the drying-wetting cycles until they are tending to be stable.2) The maximum damping ratio increases with the drying-wetting cycles until it reaches stable value.3) Under the drying-wetting cycles，the attenuations of the dynamic elastic modulus and dynamic compressive strength of the improved soil decrease with the increase of confining pressure，while the increment of the damping ratio decreases with the increase of confining pressure.