In this article, the acoustics noise characteristics under the control of blowing in the direction perpendicular to the incoming velocity at the separation point of the leading edge of the square cylinder were studied by numerical simulation, and the flow field and sound field characteristics of the three-dimensional square cylinder at zero angle of attack were studied. Under the control conditions of fixed blowing speed of 3 m/s and fixed blowing speed ratio (blowing speed/incoming speed = 0.1), change the incoming speed, and explore the blowing noise reduction mechanism and blowing control effect.