The invention relates to a novel cross-diamond searching method. Firstly, a crosslet mode is adopted for pre-search to find a minimum block-matching distortion (MBD) point, the MBD is taken as a center to construct a large cross searching mode to find the MBD; secondly, the MBD of the large cross mode is taken as the center to start the diamond search that a large diamond is searched first, a small diamond mode is adopted for search if the MBD is positioned at the center, and the found MBD point is the final block-matching distortion point; and if not, the large diamond search is continued. Across-diamond also adopts the halfway stopping technique, and the speed for searching stationary blocks and half stationary blocks is improved obviously; and the modified partial distortion criteriongreatly reduces the computational complexity without influencing the distortion factor. The laboratory result shows that the novel cross-diamond searching method respectively saves 41 percent and 16 percent of searching points compared with the diamond searching method and the cross-diamond searching method under the circumstances that the signal-to-noise ratio is less reduced or even is not reduced; compared with other prevalent block-matching motion estimation methods, the novel cross-diamond searching method has higher searching speed and less distortion degree.