Abstract: The outlet angle of air curtain is one of the key factors which affect the effectiveness of dust-isolating at fully-mechanized face. Based on the prototype of 1528 full-mechanized work face of Gequan coal mine, Hebei Jinniu Energy & Resources Co, LTD, the flow field and the dust distribution under different outlet angles of air curtain was numerically simulated, and the influence of the outlet angles of air curtain on its dust-isolating effectiveness was analyzed. The study shows that different outlet angles of air curtain can produce different effects, and the outlet angles with 5-10 degrees at fully-mechanized face is reasonable, which can ensure that the working area of coal cutter driver is at the lowest dust concentration. At last, the conclusion from numerical simulation was verified by field test.