Vegetation cover and its pattern generally determine the mechanisms in the runoff and sediment reduction under different flow rates. In this paper, the responses of sediment yield to the interaction effects of vegetation cover age and slope positions were revealed through field experiments, including the lowest coverage pattern, relatively concentrated distribution on the upper of the slope, relatively concentrated distribution on the middle of the slope, relatively concentrated distribution on the lower of the slope, and the highest coverage pattern. Then the relation between hydrodynamic connectivity of slope and soil erosion were analyzed by three kinds of hydrological connectivity indexes (FL, FL_r, FL_s). The results showed that: (1) Vegetation cover and its pattern are important factors affecting slope soil erosion process. The sediment yield of the slope with vegetation coverage of 13.5% was about 2.36 and 3.02 times of the slope with coverage of 34.0%, respectively. At the same time, compared with relatively concentrated distribution on the upper and middle of the slope, relatively concentrated distribution on the lower of the slope was mostly in the slope. The regulation functions on runoff and sediment with the grass strip relatively concentrated distribution on the lower part of the slope were generally worse. Among them, the runoff amount increased by 16.42% and 8.00%, respectively, and the sediment yield increased by 26.53% and 23.56%, respectively. However, with the increase of the flow rates, the gap between the yields of runoff and sediment in different vegetation coverage was reduced. (2) FL, FL_r and FL_s, the important indexes of hydrological connectivity, exhibited linear correlation relationship to vegetation coverage. Meanwhile at the condition of three kinds of grass strip positions, the difference of FL was obvious. Under the experimental conditions, compared with the relatively concentrated distribution on the middle and lower of the slope above, the FL on the relatively concentrated distribution on the upper slope were decreased by 10.89% and 18.33%, respectively. By the research, there was no significant covariability has been found between the FL_r and FL_s with vegetation patterns. But it could flexibly reflect the changes in hydrological connectivity under different test conditions. (3) There were significant correlations between the hydrological parameters and slope soil erosion. And the increase of FL_r and FL_s and the decrease of FL could cause an exponentially reduction in the amount of runoff yield and sediment production. Thus, FL, FL_r, and FL_s can be used to indicate the hydrodynamic parameters of slope surface water flow and sediment yield in the change. The results have reference value for deep understanding of slope erosion process and quantitative evaluation of hydrological connectivity and vegetation and slope erosion, providing evaluation of random erosion prediction model and regional ecological environment construction.