Abstract:This study explored the feasibility of ecological grass furrow to assist drainage and control non-point pollution in agricultural land of southwest China. Experiments were conducted in farmland block unit. Traditional soil furrow in farmland plots was taken as CK. Through the scouring test of the ecological grass furrow to explore the benefits of ecological grass furrow to runoff pollutant reduction. This experiment used simulated sewage,according to different requirements to adjust the sewage composition to explore the reduction effect of ecological grass furrow on pollutant. The research results showed: (1) The 5° agricultural land furrow had a certain reduction for the sewage runoff COD load, and the reduction was between 8.86% to 14.00%. However, when the ecological grass furrow gradient reached 10°, the COD pollution load in the runoff increased by 20.38% to 33.02%. (2) For the removal efficiency of total nitrogen, it was found that the total nitrogen load in the runoff was significantly higher in agricultural land furrow than that in the traditional soil furrow, and the removal efficiency ranged between 2.46% and 33.39%. (3) For the total amount of phosphorus loss, when the flow rate was 4.5 L/min, the phosphorus loss in the ecological grass furrow was larger than the designed runoff of 3 L / min, and the difference of phosphorus loss was between 0.005 9 and 0.037 7 g/m2, the rate was between 4.71% and 25.02%. When the agricultural land furrow reached 5°, the loss of phosphorus in furrow increased with the increase of runoff, and reached 63.32%. When the agricultural land grass furrow gradient reached 10°, the proportion of phosphorus loss in furrow increased with the sediment loss, and reached 70.95%.