A field erosion simulation experiment was carried out to study overland flow soil erosion process under 2 terrace types (soil, stone), 3 terrace ridges (1, 2, 3 ridge), 1 slope gradients (10°), and 3 water flow rates (0.5, 1, 1.5 m³/h). The hydrodynamic characteristics of soil erosion in overland flow under terraced field measure were analyzed. The results showed that the terrace ridge had a great influence on the flow state of the overland flow. The Increasing in the number of terraces could reduce the fluctuation of the overland flow. The influence of terrace types on the Reynolds number was relatively small. The overall soil detachment rates increased with the increase of flow rates. Under the same flow conditions, the soil detachment rates increased first and then decreased, and gradually stabilized. The correlation between the two was fitted by exponential function regression equation (R²>0.840). For the similar terrace type and field width, and under the same conditions, the soil separation rates were negatively correlated with the number of the field, and the drag coefficient was negatively correlated with the flow. The soil separation rates and the drag coefficient were negatively correlated. The research results could be great significance for understanding the process and law of soil erosion on overland flow, and also provide reference for the establishment of physical model of overland erosion.