This study explored the effects of rainfall intensity and slope gradient on soil erosion and nutrient loss under two rainfall intensities (50 and 75 mm/h) and four slope gradients (5°,10°,15° and 20°) through simulated rainfall experiments. The results were as follows: (1) When the rainfall intensity increased from 50 mm/h to 75 mm/h on the same slope, the runoff yield time was advanced by 2.75 ~ 4.79 min. (2) On the same slope, with the increasing of rainfall intensity, the cumulative runoff and cumulative sediment yield increased by 12.53 ~ 15.80 mm/m2 and 0.47 ~ 3.61 kg/m2, respectively, and the increase ranges were 1.24 ~ 1.31 times and 0.77 ~ 2.90 times, respectively; there was a critical slope gradient in the process of slope erosion, and it was about 15°. (3) The loss of nitrogen in the runoff was dominant, and the amount of nitrogen loss in sediment was low, which accounted only for 1.4% ~ 9.7% of total nitrogen loss in runoff; when the slope gradient was low, the loss of phosphorus was mainly caused by runoff loss, while with the increasing of the slope gradient, it was mainly caused by sediment loss. (4) The concentration of total nitrogen loss in runoff had obvious linear positive correlation with runoff intensity, and there was a significant positive linear correlation between total nitrogen and total phosphorus loss and sediment yield rate.