[Objective]To explore the variation patterns and cross-sectional distribution characteristics of rill erosion and its morphological features. [Methods]Indoor artificial simulation rainfall experiments and 3D laser scanning were conducted to analyze the distribution of runoff, sediment yield, and rill morphological characteristics of rill erosion under different rainfall and slope conditions. [Results] (1)When the rainfall intensity increased, the runoff and sediment production increased significantly; When the rainfall intensity is 90mm/h, the contribution rate of rill erosion to the total erosion can reach more than 90%. (2)Rill width, depth, width-to-depth ratio and rill splitting degree were significantly affected by rainfall intensity, and all showed varying degrees of increase; The rill splitting degree and the maximum depth of rill showed a significant positive correlation with the amount of rill erosion. (3)The rill cross-sectional varies greatly along the slope direction which the collapse of the gully wall is obvious, When the rainfall intensity is 60mm/h, the rill cross-sectional is mostly distributed in a "narrow shallow" shape, When the rainfall intensity is 90mm/h, the rill head and the bottom are “narrow and shallow”, in the middle is “wide and deep” in general, the rill erosion in the middle is more severe. (4)When the rainfall intensity is 60mm/h, the overall value range of rill cross-sectional index is 0.46～0.79, 0.41～0.85 in 90mm/h rainfall intensity; When the rainfall intensity is 60mm/h, the volatility of rill cross-sectional index increased with the increase of slope gradient, indicate that spatial differentiation of rill cross-sectional is more obvious, also showed that variation of the rill cross-sectional tends to be irregular. [Conclusion]the research results can provide some theoretical support for rill erosion prevention and cure.