With the increasing development of aircraft transport, people have paid more and more attention to the noise generated from aircraft. In the take-off and landing stage of large aircraft, the high-lift device as the main airframe component radiates much noise which is a major part of the aircraft total noise, and the high-lift device noise is the key factor whether the aircraft can further reduce the noise and meet the airworthiness requirement in the future. This paper makes an experimental investigation on the aerodynamic noise of the multi-section airfoil 30P30N of the high-lift device. The aeroacoustic experiment is conducted in Beihang University D5 aeroacoustic wind tunnel, the closed test section of which is composed of Kevlar cloth and perforated plate for the aerodynamically closed and acoustically open condition. The far-field noise characteristics and the noise source location are respectively measured by the microphone and the microphone array, and the wavelet transform method is introduced to analyze the aeroacoustic time-frequency characteristics for completely revealing the aeroacoustic mechanism of the multi-element configuration.