The invention belongs to the technical field of medical image-based image processing, and particularly relates to a method for automatically extracting a tracheal tree from a chest CT image. The method comprises the steps of obtaining main tracheae and main bronchi; according to a 3D region growing segmentation mode and information of the obtained main tracheae and main bronchi, building an adaptive threshold 3D region growing segmentation model and an adaptive threshold leakage model; by utilizing the adaptive threshold 3D region growing segmentation model and the adaptive threshold leakage model, extracting second tracheal branches of the chest CT image; according to intermediate information of the extracted second tracheal branches, adjusting parameters of the adaptive threshold 3D region growing segmentation model and the adaptive threshold leakage model, and then extracting third tracheal branches of the chest CT image; and based on an obtained tracheal tree topology structure, extracting terminal tracheal branches, and obtaining the tracheal tree of the chest CT image. According to the method provided by the invention, the tracheal segmentation precision of extracting the tracheal tree from the CT image is improved and the extraction time is shortened.