Inverse synthetic aperture radar (ISAR) is an important tool for non‐cooperative ship imaging, and one key step of ISAR imaging is range alignment. To achieve the range alignment with high precision, efficiency and robustness, an improved ISAR range alignment method based on maximum contrast is proposed in this paper, which takes the maximum contrast of average range profile as the optimisation criterion to perform the range alignment. Compared with the minimum entropy method, this method is with lower computation complexity and faster convergence rate. Thus the method proposed in this article is more effective and more robust. Computer simulation and real data experiment validate the effectiveness and robustness of the proposed method.