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For undisturbed loess with water sensitivity and dynamic vulnerability, which is often in a state of damage accumulation due to the influence of natural factors (the fluctuation of groundwater level, rainfall infiltration/evaporation, and seismic load), the impact of relevant engineering problems is significant, and the disaster-causing process is complex. Cyclic simple tests were used to illustrate the behaviour of the dynamic shear modulus of loess exposed to various factors of dry-wet(D-W) cycles and stress conditions (D-W cycles times N , lower limit water content w 1 , and consolidation stress σ v). Using scanning electron microscopy (SEM), we assessed the inherent damage mechanism under D-W cycles. The findings show that the D-W cycles considerably affect the dynamic shear modulus of undisturbed loess, with the strongest effect occurring during the first D-W cycles. Based on the Hardin hyperbolic model, the stress exponent n is a specific parameter of w 1. In addition, the relationship between N and G 0 / P a /(σ v / P a) n is a power function, and G 0 / P a /(σ v / P a) n drops as w 1 and N increase. The fitting parameters a of the dynamic shear modulus ratio normalization model are not sensitive to σ v / P a , D-W cycles times N , and lower limit water content w 1. Based on the dynamic shear modulus, a damage degree prediction method considering N , w 1 , and σ v is established. The results can provide a theoretical reference for earthquake disaster prediction in collapsible loess areas. [Display omitted] • Dry-wet cycles test, cyclic simple shear test, and SEM test were carried out. • The behavior of dynamic shear modulus under the coupled action of dry-wet cycles and dynamic load was investigated. • Method were proposed and verified to predict dynamic shear modulus under dry-wet cycles. • This study can provide reference for earthquake disaster prediction in loess area. [ABSTRACT FROM AUTHOR]