Wake?guided torpedo poses a serious threat to surface ships． In order to extend the passive interception mode of suspension interception missile from the non?wake region to the wake region and intercept wake homing torpedo， characteristics of the noise in the wake need to be studied and the environmental noise characteristics of the interception projectile in the wake area need to be analyzed． In this paper， the noise of the ship wakes in different tonnage ships is studied based on the suspension interceptor missile． Based on the theory of probability combining with higher order cumulants， this paper calculates the variation rule of wake flow noise’s skewness and kurtosis varying with wake age； noise skewness is to determine whether the noise meets symmetrical distribution， and noise kurtosis to determine whether the noise is Gauss signal． From comparison of the kurtosis and skewness of measured data with those of simulation data， a conclusion is draw that the noise environment of ship wake can be approximated as the Gauss signal， which follows the symmetrical distribution and this distribution is not related to the tonnage of ship．
