In this paper, the computational fluid dynamic method was applied to simulate the flow field around 2D multi-element airfoil with droop nose devices (DND) at leading edge. A typical 2D airfoil NACA0410 was used to design the multi-element airfoil. The effect of four factors used to design DND on aerodynamic characteristics of a multi-element airfoil was studied. The result shows that, 1) in the linear segment, increases in chord length and deflection angle both have negative effect on lift, but the angle between the hinge height and the trailing edge has little effect on lift; 2) close to /at stalling point, increases in chord length and trailing edge angle can obviously increase lift; lift increases when deflection angle is less than 26° and lift increases as hinge height decreases, but decreases when hinge height is less than 2 mm; 3) 4 parameters mainly affect the fluctuation of two suction peaks at the leading edge. These four parameters should be comprehensively considered and applied during design.