The passive radar is a new radar system based on third-party non-cooperative radiation sources, which has unique advantages in micro-Doppler target classification and recognition. Its characteristics determine that the micro-Doppler effect parameter estimation method must have a good anti-noise performance and a small amount of calculation. In view of these considerations, this study presents a new idea of helicopter rotor parameter estimation using an echo flicker in the time-frequency domain based on the micro-motion signal model for the passive radar. The echo flicker parameters are extracted by accumulating the amplitudes of the positive and negative frequency axis data in the time-frequency diagram. The dictionary matrix is constructed based on the inherent characteristics of the micro-motion signals. The blade length, blade number, rotor speed, and other parameters are estimated using the orthogonal matching pursuit algorithm. Compared with the method based on the conventional Hough transform, the proposed method is more accurate and more rapid. The simulation and experimental results prove the feasibility of this method.