During airplane’s take-off, higher lift force should be provided by wing used high lift devices, and the drag should be lower. The design basis of high lift devices with good aerodynamic characteristic is the design of the multi-element airfoil. When a multi-element airfoil is used Gurney flap, lift coefficient can be improved while drag coefficient is also increased, but the lift-to-drag ratio is reduced. In this paper, the numerical simulation method is used to study the aerodynamic characteristic of the multi-element airfoil used Gurney flap with slat in the configuration of take-off. Lift coefficient and drag coefficient of the multi-element airfoil with Gurney flap can be reduced by slat while lift-to-drag ratio of airfoil is increased. Through the comparisons of the multi-element airfoils with Gurney flap with different types of slats, the optimized multi-element airfoil with higher lift coefficient and lower drag coefficient is obtained ultimately.