Radar signal sorting is the key technology of electronic warfare, and pulse repetition interval (PRI) is an important parameter of signal sorting. In this paper, a PRI sinusoidal extraction method of modulation feature based on Empirical mode decomposition (EMD) decomposition is proposed. By defining the S function and performing EMD decomposition on it, the Intrinsic Mode Function (IMF) group obtained. Selecting the appropriate IMF component to extract the sinusoidal modulation period. Combined with the S function, the pulse sequence initially screened, and the modulation characteristics are determined according to the screening results. A pulse sorting algorithm is implemented according to the modulation characteristics. The simulation results show that the proposed method can effectively extract the modulation information from multiple radar pulses with different modulation periods, such as the modulation period of the PRI modulated signal, and complete the sorting of the radar pulse.