The invention discloses an aeroacoustics principle-based flow rate measurement device and a method thereof. The device comprises a rectifying device, an upstream section of a main pipe, a measuring section and a downstream section of the main pipe which are connected in sequence, wherein the sections of the upstream section of the main pipe and the downstream section of the main pipe are round orsquare; and the rectifying device is silk screen rectification or flow deflector rectification. The method converts flow velocity into periodic pressure fluctuation by using the aerodynamical principle so as to greatly reduce the difficulty of flow rate measurement. The device based on the method comprises the rectifying device, the upstream section of the main pipe, the measuring section and thedownstream section of the main pipe which are connected in sequence. The device and the method measure the fluid flow rate of the main pipe through electric signals responded in a pressure sensor in the measuring section, and have the advantages of convenient assembly, simple structure, small interruption on pipeline fluid, small additional resistance, stable measurement and short response time.