In order to study the erosion characteristics and hydraulic mechanism of cinnamon soil slope during long-term rainfall erosion,10 consecutive rainfall experiments were carried out under 60,90 mm/h rainfall intensity respectively by the mean of indoor simulated rainfall experiment. The characteristics of runoff and sediment discharge,hydraulic parameters change,and the relationship between runoff sediment concentration and hydraulic parameters were discussed. The results showed that: (1) Under the premise that the same rainfall intensity and rainfall event,the change of runoff was smaller with the increase of rainfall events number,but the sediment discharge of the sub-rainfall changed greatly. Under the rainfall intensity of 60,90 mm/h,the variation coefficient of sediment yield was 23.94% and 59.88%,and the sediment yield of the 10th rainfall was only 59.74% and 22.28% to the first rainfall. (2) The average sediment yield rate of each rainfall increased with the rainfall intensity,the runoff sediment concentration showed the decrease trend of power function with rainfall time. (3) Influenced by morphological changes of rills and soil coarsening on the slope of brown soil,the average flow velocity of 60,90 mm/h showed the descending trend of exponential function and power function in the process of erosion,respectively. Froude number showed the same trend with average flow velocity. The Darcy-weisbach resistance coefficient increased logarithmically in the process of erosion under 60,90 mm/h rainfall intensity. (4) The correlation relationship between runoff sediment concentration and average flow velocity,Froude number,Darcy-weisbach resistance coefficient and runoff power were extremely significant,respectively. The average flow velocity was the most closely related hydrodynamic parameter in the process of runoff sediment concentration change. The change of runoff sediment concentration is deeply affected by the dynamic process of average flow velocity of slope runoff.