Abstract: To estimate Doppler frequency shift (DFS) accurately and rapidly, a geometric algorithm of LEO Doppler-time was provided to adapt to different eccentricity. Based on the orbital parameters and the maximum visual elevation angle, the algorithm can get the Doppler-time characterization during the satellite's visibility window, which is irrelative to the terminal location and the satellite coordinate. Simulation results and numerical analysis indicate that the algorithm has higher precision, lower complexity and is easy for programming on-chip. And it can provide prior information for satellite communication receiver to estimate and compensate the Doppler frequency shift.