Abstract: This paper analyzes the mechanism of underwater vehicle′s radiating noise,especially the noise with linear PSD (Power Spectral Density),and predicts the line spectrum′s frequencies of dynamic device and screw propeller respectively. On the basis of the above research,the line spectrum of underwater vehicle′s radiating noise is modeled by the periodical signal. With the model,the line spectrum frequen-cies of a certain underwater vehicle′s radiating noise is predicted.