The existing multi-PD sources separation methods mostly use the time-frequency difference of PD UHF signal as the feature parameter for multi-sources signal separation, but the separation accuracy rate will be low when the SNR is low. A multi-PD sources separation method based on the characteristics of time delay sequence distribution is proposed in order to improve this situation. The rotation detection platform based on two directional antennas is used to analyze the relationship between the time delay sequence and the rotation angle of the antenna array, the two ones satisfy the cosine function relation, this corresponding relationship is adopted as the eigenvalue for multi-PD sources separation. The separation accuracy of 3 analog PD sources at different SNRs is simulated based on the time domain finite difference algorithm. Compared with the existing multi-PD sources separation method, when the signal to noise ratio is 5dB, the separation accuracy is increased from 71% to 95%. Experiments in a 220kV test substation show that multi-PD sources are accurately separated and located, and the effectiveness of the separation method is verified.