In order to study the temporal and spatial changes and relations between the conductivity of soil slope and matrix suction under the action of rainfall, a physical model test of artificial rainfall landslide was conducted, in which the resistivity was used as the monitoring quantity, combined with the conventional water content and matrix suction, and Manila grass was planted on the slope model to explore the infiltration characteristics of grass slope under three dynamic rainfall modes: uniform rainfall, front small back peak, and front peak back small. The results show that under the dynamic rainfall mode, the change of rainfall intensity can affect the resistivity and water content of soil, but there is a certain lag. Although the response time of soil matric suction is different under different rainfall patterns, the variation trend of soil matric suction is similar. Before rainfall, the matrix suction and resistivity of slope soil are higher, and gradually decrease with the increase of depth. After the rainfall, due to water infiltration, the matric suction and resistivity of surface soil decreased greatly, and the distributions on the slope have showed a trend of increasing gradually from shallow layer to deep layer. A prediction model of residual soil matric suction based on resistivity was obtained, combined with Keller's improved Archie model and VG model, which was verified by experimental data, and the results were reasonable. This model adds a new way for indirect measurement of residual soil matric suction. The research results are helpful to explore the seepage characteristics of unsaturated residual soil slope under different rainfall modes, and reveal the evolution law of the electrical conductivity and spatial distribution characteristics of matric suction of residual soil slope under rainfall, which is of theoretical and practical significance for stability analysis, monitoring and early warning of residual soil slope under typhoon and rainstorm. [ABSTRACT FROM AUTHOR]