Abstract: Doppler frequency shift of satellite signals in LEO and MEO has a character of long-range changes and quick time-variation.Based on the theories and methods of astrodynamics,the relative positions and velocities between satellites and receiving stations are computed,therefore Doppler frequency shift can be pre-estimated.The error of the estimating method is firstly analyzed;consequently,an algorithm of fast estimation and real-time compensation for Doppler frequency shift is put forward.At the same time,the visual time slices between receiving platforms and observed satellites are explored according to different situations.Simulation results and engineering practices indicate that the algorithm is simple and practical and is available for fast track and correct demodulation of satellite signals with fast and large variable frequency shift.