An aerial photograph image pickup method comprises a first step of acquiring still images along an outward route and a return route respectively when a flying object flies in meandering manner in the sky over an object range to be measured, a second step of preparing a stereo-image by relative orientation on one set of images adjacent to each other with regard to three images adjacent to each other in advancing direction, and of preparing another stereo-image by relative orientation on one more set of adjacent images and of preparing two sets of stereo-images, a third step of connecting two sets of stereo-images by using feature points extracted from a portion of an image common to two sets of stereo-images and the portion is an overlapped portion of the three images all together, a step of connecting all stereo-images in outward route direction and in return route direction according to images acquired in the first step by repeating the procedures of the second step and the third step, a step of selecting common tie points from the images adjacent to each other in the adjacent course and of connecting the adjacent stereo-images in the course, and the aerial photograph image pickup method prepares an unified stereo-image which covers the entire object range to be measured and is represented by common three-dimensional coordinate system.