In order to enhance the target recognition probability in the inverse synthetic aperture radar (ISAR) imaging domain, the interferometric ISAR (InISAR) mode is presented to achieve the 3-D information of a target. However, the real data results of a maneuvering target are not enough, due to the difficult signal processing. In this letter, a combined processing approach is proposed to realize high-quality 3-D imagery of a maneuvering target. In the approach, the range alignment and phase adjustment are implemented together on echoes to avoid destroying the coherence of the echoes. Then, the high-quality 3-D InISAR imagery of the maneuvering target can be reached. Real data results are provided to confirm the effectiveness of the proposal.