Bridge strain close-range photogrammetry method based on unmanned aerial vehicle image

The invention discloses a bridge strain close-range photogrammetry method based on an unmanned aerial vehicle image. The method comprises the following steps: pasting a coding point at a to-be-detected position of a bridge; using the unmanned aerial vehicle to respectively shoot two groups of images including all coding points before and after the deformation of the to-be-detected area at a plurality of positions in the horizontal facade from different angles at a fixed focal length; carrying out automatic processing, identification and positioning on the image; performing three-dimensional space point reconstruction by using a photogrammetry algorithm; and processing the reconstructed three-dimensional point coordinate data by using an MATLAB tool so as to calculate the strain in the to-be-measured area of the bridge. A complex sensor does not need to be installed on the structure, meanwhile, compared with a traditional non-contact detection means, a measurement method based on an unmanned aerial vehicle ima