Open AccessIn order to deal with the acoustic radiation from rotating sources, this paper describes a frequency-domain numerical method for predicting sound radiation. The method is based on the analytical Green’s function of rotating monopole and dipole source in free space. Sound radiation model is established and characteristics of sound field are discussed by numerical simulation and the relationship between radiated sound frequencies and acoustic nature frequency of source, angular frequency and its harmonics can be revealed .The radiated sound field has a strong directivity, fundamental frequency transmitting in the rotary shaft direction and harmonics spreading along radial direction and frequency shift phenomena appearing clearly in higher rotating speed of source. The method has a theoretical significance for exploring the low-noise rotating machinery.