A DR radiography lung contour extraction method based on fully convolutional network, which includes the steps: Establish the fully convolutional network structure of lung contour segmentation； Conduct off-line training on the weighting parameters of the fully convolutional network； Read DR image and weighting parameters of the fully convolutional network； Input DR image into fully convolutional network and output segmentation results of image through network terminal with network layer-by-layer feedforward. Establish lung contour in accordance with segmentation results.
