Abstract: The triangular flexible and rigid vortex generators with a side length of 10 mm were installed at different chord lengths on the leading edge of the upper wing of the two-dimensional NACA0018 airfoil to control the separation of the leading edge of the airfoil. The experiment was carried out in a low-speed DC wind tunnel. Its Reynolds number was Re=1.1×10⁵ with airfoil chord length as the characteristic length. A monofilament hot wire anemometer was used to measure the wake velocity profile. The control effects of the triangular flexible and rigid vortex generators on the separation of the leading edge of the airfoil were studied respectively. Experimental results show that, compared with rigid vortex generators, flexible vortex generators use the incoming flow energy to achieve adaptive control and move the shear layer down, thereby significantly suppressing leading edge separation.