Bridge support displacement measuring method based on three-dimensional laser scanning

The invention discloses a bridge support displacement measurement method based on three-dimensional laser scanning, and the method comprises the steps: firstly determining the position of a support on a bridge according to the constructed and formed bridge, inserting a steel nail into the support, and installing a target at the same time; secondly, arranging an observation station below a pier corresponding to the support, erecting three-dimensional laser scanning equipment at the position of the observation station, and sequentially performing point cloud scanning at the position of the observation station to obtain three-dimensional point cloud information; the target center coordinate of the target is recognized to serve as the position of the support upper seat plate under the local coordinate system of the observation station; after a period of time, scanning is repeated once to obtain a new coordinate of the upper seat plate of the support; then, local coordinate systems of all the stations are transfor