Abstract: In order to solve the registration problem of sequence images in forward-looking imaging radar, this paper proposes an image registration algorithm, which is based on combination of imaging theory of forward-looking array radar and Hausdorff distance. First the sensor information is used to estimate range offset between images. Then the length of array aperture is modified and image resolution could be corrected. To solve the difficulty in angle estimating which is brought by the isotropy of landmine, the Hausdorff distance is introduced here. Combined with imaging theory, the Hausdorff distance is mapped from image field to echo field. Consequently the resolution correction and image registration are incorporated, which could improve the speed and precision of registration. It is proved by real data that the method is applicable to forward-looking array radar and the registration precision and detection rate are also improved.