An aerial photograph image pickup method, comprising: a first step of acquiring still images along an outward route and a return route respectively when a flying object flies in meandering manner up in the sky over an object range to be measured; a second step of, from three still images (S1, S2, S3) adjacent to each other in an advancing direction, preparing a first stereo-image in a first three-dimensional coordinate system by relative orientation on first two still images (S1, S2) adjacent to each other from said three still images using at least five orientation points ( to) that are common feature points extracted from a portion where said first two still images are overlapped on each other, and of preparing a second stereo-image in a second three-dimensional coordinate system by relative orientation on latter two still images (S2, S3) adjacent to each other from said three still images using at least five orientation points ( to) that are common feature points extracted from a portion where said latter two still images are overlapped on each other; a third step of connecting said first stereo-image and said second stereo-image using a still image which is common to said first stereo-image and said second stereo-image and wherein at least three connecting points that are feature points extracted from a portion where said three still images are overlapped all together are used, and performing coordinate conversion of said second stereo-image using said first three-dimensional coordinate system as reference; a step of connecting all stereo-images in the outward route and in the return route by repeating the procedures of the third step; wherein the stereo-images in the outward route and the return route are prepared according to the second step from the still images acquired in the first step; a step of selecting common tie points from the still images adjacent to each other across the outward route and the return route and of connecting the adjacent stereo-images across the outward route and the return route based on the common tie-points; and a step of preparing a unified stereo-image which covers the entire object range to be measured and is represented by a common three-dimensional coordinate system, characterised in that an overlapping ratio overlapped in the advancing direction is 70% to 90%, and a sidelapping ratio overlapped between the outward route and the return route is 40% to 60%. a first step of acquiring still images along an outward route and a return route respectively when a flying object flies in meandering manner up in the sky over an object range to be measured; a second step of, from three still images (S1, S2, S3) adjacent to each other in an advancing direction, preparing a first stereo-image in a first three-dimensional coordinate system by relative orientation on first two still images (S1, S2) adjacent to each other from said three still images using at least five orientation points ( to) that are common feature points extracted from a portion where said first two still images are overlapped on each other, and of preparing a second stereo-image in a second three-dimensional coordinate system by relative orientation on latter two still images (S2, S3) adjacent to each other from said three still images using at least five orientation points ( to) that are common feature points extracted from a portion where said latter two still images are overlapped on each other; a third step of connecting said first stereo-image and said second stereo-image using a still image which is common to said first stereo-image and said second stereo-image and wherein at least three connecting points that are feature points extracted from a portion where said three still images are overlapped all together are used, and performing coordinate conversion of said second stereo-image using said first three-dimensional coordinate system as reference; a step of connecting all stereo-images in the outward route and in the return route by repeating the procedures of the third step; wherein the stereo-images in the outward route and the return route are prepared according to the second step from the still images acquired in the first step; a step of selecting common tie points from the still images adjacent to each other across the outward route and the return route and of connecting the adjacent stereo-images across the outward route and the return route based on the common tie-points; and a step of preparing a unified stereo-image which covers the entire object range to be measured and is represented by a common three-dimensional coordinate system, characterised in that an overlapping ratio overlapped in the advancing direction is 70% to 90%, and a sidelapping ratio overlapped between the outward route and the return route is 40% to 60%.