The present invention relates to a photogrammetry system and method. The photogrammetry system comprises: photographing devices capable of photographing an object at a predetermined time interval; and, a data processing device capable of calculating an actual length of the object or a certain portion on the object according to a length of the object or a certain portion on the object in the images obtained by the photographing devices and a distance of the object in the two images, wherein the object moves at a speed V; the photographing devices photograph the object for two times at a time interval t; the distance of the object in the two images obtained by the two times of photographing is Dp; the length of the object or a certain portion on the object in the images is Lp; and, the actual length L of the object or a certain portion on the object may be obtained by the following formula: L = Lp × Vt Dp .