Disclosed herein is a plant disease and pest control method using aerial photography and spectral remote sensing technology to record and analyze crop orthographic images. After building meshes from a dense point cloud or 3D depth map, orthographic images are generated. Then, the numbers of crop pest insect, crop leaf infestation area, and the ratio between leaf and its farmland area are calculated using deep learning techniques. After that, the growth curve of the pest population is established via modeling techniques and a pest and disease prediction model is established to determine the optimized timing for pesticide spraying.