Abstract: Inspired by the owl's high-efficiency and low-noise flight mode, this work studies the bionic structure of its coverts, and designs a new type of flexible serrated vortex generators with different flexible materials, which are hinged at several different locations of a two-dimensional NACA0018 airfoil in the wind tunnel, to study the flow separation control effect of flexible materials with different areal densities. In the experiment, a single-point sweep of a hot wire anemometer with high time resolution was used to measure the flow field information in the wake region, and the wavelet analysis was used to extract multi-scale structures in the time-frequency domain. After points with high kinetic energy were obtained, a two-channel hot-wire measurement was used to acquire synchronous velocity data at different locations, and the correlation between disturbances at different spatial positions was obtained in both the time and frequency domains through a cross-correlation analysis. A high-speed CCD camera was used to record the movement and adaptive deformation of the vortex generators, and the relation with disturbance vortices was analyzed. The experimental results suggest that, when installed on the trailing edge, medium density vortex generators can effectively absorb 34% of the nearby turbulent kinetic energy. The shear layer moves downstream by 0.05 times the chord length, and the low-frequency power spectral density of the trailing-edge and leading-edge shear layer is decreased by 70% and 50%, respectively. Large-scale structures of the leading-edge shear layer were broken into small-scale ones, and the correlation between the leading-edge and trailing-edge shear layers in the frequency domain was considerablely increased. When the installation location moves upstream, perturbations generated under the adverse pressure gradient were shifted to a low-frequency bandwidth, and the large-scale vortex can induce the separation bubble to move downstream by 0.1 times the chord length.