A method and device and a system are disclosed. The method may include: obtaining, by a measurement device, a first image that is obtained by photographing an antenna at a first position (101); mapping M characteristic points included in the first image into a first three-dimensional spatial coordinate system, to obtain M three-dimensional space points that are in the first three-dimensional spatial coordinate system and that have a mapping relationship with the M characteristic points (102), where a first mapping photographing direction is parallel to a direction of an axis in the first three-dimensional spatial coordinate system, and the first mapping photographing direction is obtained by mapping a photographing direction of photographing the first image into the first three-dimensional spatial coordinate system; and obtaining a downtilt of the antenna according to a first angle and/or obtaining an azimuth of the antenna according to a second angle (103).