Lung tumors are very large with benign possibilities, but lung tumors cannot be judged whether they are benign or malignant possibilities by judging from their size, but need to be clarified based on the features of lung tumors on imaging and confirmed by pathological examination. Benign lung tumor tissues and normal tissues show obvious demarcation line on imaging, which is not accompanied by short burr, lobulation, pleural depression sign, pleural pulling sign and other features. Benign lung tumors grow more slowly and do not invade normal tissues, therefore, a large lung tumor can also be benign. In case of malignant lung tumors, the tumor tissues show one or more of the following features on imaging: irregular peripheral morphology, burr-occupation at the edge, short burr, lobulation, pleural depression sign, pleural pulling sign, etc. Malignant tumors grow more rapidly, and the tumors invade into the normal tissues to affect the normal tissue function. When lung tumor is diagnosed, it can be further diagnosed through pathological examination under the guidance of doctor to clearly diagnose the benign or malignant nature of the tumor and actively cooperate with the treatment.