To overcome the influence of non-ideal factor on the performance of moving target indication, such as the channel gain and phase response error and image registration error, an improving clutter rejection method is proposed. The algorithm combines the minimum variance clutter rejection method and the steering vector clutter rejection method. Firstly, the weight vector of minimum variance clutter rejection is calculated to construct registration image. Then clutter orthogonal subspace is calculated with registration image. Finally, clutter rejection is implemented with orthogonal subspace method. Theoretical analysis and experimental results show that the proposed method performs well and it can obtain higher SCNR than the minimum variance clutter rejection method and steering vector clutter rejection method when both image registration and channel amplitude and phase errors are big.