A measurement method, applicable to an image acquisition device, comprising: acquiring image data to generate an image data file (S101); capturing an object to be measured in an image corresponding to the image data file (S102); enclosing the object to be measured with a target rectangle, the target rectangle having a pair of sides parallel to the horizontal line going through the center point of the image and being a rectangle with a minimum area among rectangles that can enclose the object to be measured; and taking a vertical distance between a side of the pair of sides that is closer to the ground and the horizontal line going through the center point of the image as a first distance (S103), and taking a vertical distance between a side of the pair of sides that is farther from the ground and the horizontal line going through the center point of the image as a fourth distance; calculating a second distance, which is a horizontal distance between the object to be measured and the image acquisition device based on the first distance, an installation height of the image acquisition device, a pitch angle of the image acquisition device, a height resolution of the image, the height of an imaging plane of the image, and a focal length of an optical lens of the image acquisition device (S104); lens, and calculating a height of the object to be measured based on the second distance, the fourth distance, the installation height of the image acquisition device, the pitch angle of the image acquisition device, the height resolution of the image, the height of the imaging plane, and the focal length of the optical lens. acquiring image data to generate an image data file (S101); capturing an object to be measured in an image corresponding to the image data file (S102); enclosing the object to be measured with a target rectangle, the target rectangle having a pair of sides parallel to the horizontal line going through the center point of the image and being a rectangle with a minimum area among rectangles that can enclose the object to be measured; and taking a vertical distance between a side of the pair of sides that is closer to the ground and the horizontal line going through the center point of the image as a first distance (S103), and taking a vertical distance between a side of the pair of sides that is farther from the ground and the horizontal line going through the center point of the image as a fourth distance; calculating a second distance, which is a horizontal distance between the object to be measured and the image acquisition device based on the first distance, an installation height of the image acquisition device, a pitch angle of the image acquisition device, a height resolution of the image, the height of an imaging plane of the image, and a focal length of an optical lens of the image acquisition device (S104); lens, and calculating a height of the object to be measured based on the second distance, the fourth distance, the installation height of the image acquisition device, the pitch angle of the image acquisition device, the height resolution of the image, the height of the imaging plane, and the focal length of the optical lens. <EOS>