The hydrodynamic characteristics of the overland flow with a geocell slope are different from those of traditional flows because of its special structure. In this paper, a hydraulic flume with different slope gradients is used to study the hydrodynamic characteristics of the overland flow with geocell. The differences of flow characteristics between the overland flow with the geocell slope and the traditional flows are studied, and the hydrodynamic characteristics are obtained, including the flow pattern, the flow velocity and the hydraulic friction factor for the slope flow with geocell under different flow rates and slope gradients. The results show that there is a positive power function relationship between the rill depth of the slope surface （h） and the drag coefficient of the Darcy Weisbach （f）. There is a positive logarithmic function relationship between the drag coefficient f and the Reynolds number Red, and there is a negative power function relationship between the drag coefficient f and the Froude number Fr.
