Abstract: The present disclosure relates to a 2D-3D medical image registration method. The method includes obtaining a preoperative CT image and an intraoperative Xray image of a target bone block, inputting the preoperative CT image and the intraoperative Xray image into a depth-based learning-based regression network, and roughly estimating an initial spatial posture of the target bone block by using the regression network; and adjusting a projection of the preoperative CT image based on the initial spatial posture to generate a DRR image; and inputting the DRR image, the intraoperative Xray image, and the preoperative CT image into a pre-trained correspondence point relationship estimation network, estimating a feature point corresponding relationship between the DRR image and the Xray image by using the corresponding point relationship estimation network, and optimizing the initial spatial posture according to the feature point corresponding relationship to obtain an optimized spatial posture.