The invention relates to a transformer station noise coupling separation method. The transformer station noise coupling separation method includes the following steps: S1, performing spectrum analysis on the original signal of noise, sorting 50Hz of resonant frequency and the resonant frequency taking 50Hz as the fundamental frequency according to energy from high to low, obtaining a plurality of resonant frequencies which are taken as the noise frequency of the main body of a transformer; S2, taking the original signal as an initial residual error signal, separating the noise of the main body of the transformer from the original signal successively, and obtaining a residual error signal; S3, separating the corona noise from the residual error signal obtained from the step S2; and S4, taking the residual noise as other noises, including the blower fan noise and the background noise. Compared with the prior art, the transformer station noise coupling separation method constructs a coupling function according to the intrinsic characteristics of the noises generated from different noise sources of the transformer station, and organically considers the original noise source characteristics, thus having high practicality, and being able to effectively separate the main body noise of the transformer, the corona noise and other random noises. The transformer station noise coupling separation method can provide means and methods for transformer station noise environmental impact assessment, noise treatment and part evaluation.