Rainfall seepage is a main factor leading to landslides. Based on the field test of rainfall, the model of loess slope was made base upon similarity ratio. Firstly, the model was performed with 25 mm/h medium intensity artificial rainfall. Secondly, the model of loess slope has been operated by shaking table test. 12 humidity sensors were arranged along the slope toe, slope face and slope shoulder. The results of test showed that the humidity of the slope shoulder was the largest, followed by the slope toe, and the slope surface was the smallest. Different seismic accelerations have a significant impact on moisture transfer in loess slope, which were 200, 500 and 800 gal respectively. The change of humidity at 50 mm from the slope is obviously greater than 175 mm. Moisture transfer is composed of rainfall seepage and seismic liquefaction. As loaded to 800 gal, the loess has emerged to obvious loess liquefaction. The results of test showed that the seismic acceleration have a significant influence on the moisture transfer in loess slope. The change of humidity varies greatly with different slope positions. As the slope depth increases, the change of humidity smaller. When the depth from the slope is small, the change of humidity is the most in slope toe, and when the depth from the slope is large, the change of humidity is the most in slope shoulder. Studying the law of moisture transfer in loess slope after rainfall seepage can provide a theoretical basis for the design and treatment of loess slopes.