The invention provides a structure detection method, a structure detection device, and an unmanned aerial vehicle system for structure detection. The method comprises the following steps: acquiring the distances of range finding sensors to the surface of a detected structure, acquired by at least three range finding sensors positioned on the same plane; obtaining an angle between the surface of the detected structure and the plane of the at least three range finding sensors according to the distances of the range finding sensors to the surface of the detected structure, respectively acquired by the at least three range finding sensors; and obtaining the quantitative geometric characteristic information of defects existing on the detected structure or the surface of the detected structure according to the angle and image data of the surface of the detected structure. The device comprises a distance acquiring module, an angle acquiring module and a dimension measuring module. The quantitative detection result of the geometric characteristic information of defects existing on the detected structure or the surface of the detected structure can be obtained by the structure detection method, the structure detection device and the unmanned aerial vehicle system for structure detection.