This paper discusses the imaging algorithm of high speed space targets in ground based bistatic Inverse Synthesize Aperture Radar (Bi-ISAR) system. Firstly, the system model and the target echo signal form are given; secondly, the influence of space target moving on two dimension resolution is analyzed. Based on the above, the echo signal is analyzed and disposed, when the targets moves in high speed, it will induce the Residual Video Phase(RVP) and ambulating factor pulse inner ,then the compensation function is constructed to compensate the influence, furthermore, the Keystone transformation is used to eliminate the MTRC and the whole imaging flow is given. Finally, the simulation imaging of satellite target is given to validate that the infection of the RVP and ambulating factor pulse inner can't be ignored. The comparison between the before and after compensation images shows the effectiveness and practicability of the proposed algorithm.