The invention relates to a small unmanned aerial vehicle remote sensing-based slope deformation detection and calculation method which comprises the following technical steps: arranging and measuring image control points on the spot according to characteristics of a slope; acquiring a high-definition image of the slope on the spot by virtue of a small unmanned aerial vehicle remote sensing system; processing and adding the image control points to generate a three-dimensional slope point cloud by virtue of digital photogrammetry; performing checking and optimization to generate a three-dimensional slope point cloud with high absolute position accuracy; highly accurately registering three-dimensional slope point clouds of earlier and later periods; performing slope deformation detection and calculation on the basis of high-accuracy remote sensing results of an earlier period and a later period.