Aiming at the negative correlation between the depth of field and resolution of surgical microscopes, this study proposed an image acquisition scheme based on an ophthalmic surgical microscope system to expand the depth of field under the premise of high-resolution imaging. The involved binocular images have a large depth of field and high resolution respectively. Subsequently, a binocular image-fusion algorithm was designed according to the imaging characteristics obtained after the transformation. The involved focus detection results were employed as initial fusion decision maps, which were subsequently refined by combining the color and texture information of the images. The detailed information was effectively fused through double-scale decomposition. Experimental results show that the proposed scheme and fusion algorithm can be used to highlight the details of high-resolution images by preserving the clear range of large-depth-of-field images. The depth-of-field enhancement achieved using the proposed algorithm is >50% compared with that of the original algorithm. Overall, the proposed method is suitable for visual observation of large-depth-of-field and high-resolution surgical microscopic images, intraoperative two- and three-dimensional displays, and postoperative image preservation and analysis.