The invention belongs to the technical field of power systems and automation thereof, and discloses a forced oscillation disturbance source positioning method based on frequency band-dividing parallel computation. A preset frequency range is divided into a plurality of frequency bands for parallel computation; as for each frequency band, through setting each data window length and each sampling frequency, analyzed data points are reduced; each frequency band adopts an asynchronous computation mode, other frequency bands do not need to be waited after one-round analysis computation, a result is refreshed and new data are obtained for next-round analysis, dissipation power of a unit, a transformer and a line is calculated, a suspected oscillation source related element is screened according to a threshold value, oscillation elements are grouped according to a dominant mode phase angle, and elements with advanced phases in the group of the suspected oscillation source elements are selected as the oscillation source unit, the related line and the transformer. The scheme is reasonably designed, and forced power oscillation warning and disturbance source positioning information timeliness can be ensured.