In order to study the influence of rammed earth properties on rainfall erosion of the Great Wall of the Ming Dynasty in northern Shaanxi in a quantitative way, quantitative simulation experiments were conducted, using models. The results show that 1) under heavy rain or in rainstorms, low-density rammed earth performs dry-wet function, and the soil loss from scouring erosion is relatively lower; 2) under the same conditions, high-density rammed earth models exhibit mainly scouring erosion and partial collapse, and the soil loss from scouring erosion is relatively higher. The soil loss from rainfall erosion shows an exponential relationship with the density of rammed earth, and they show a positive correlation within the natural soil water content range. The study enriches rainfall erosion models of rammed earth sites and offers useful reference for further study of rammed earth site erosion mechanisms under multi-factor coupling conditions.