Abstract: Lung cancer is a common clinical malignant tumor, and it has a high morbidity and mortality rate. Evaluating the pathological behavior of lung cancer is of great significance for selecting treatment options, judging the efficacy and prognosis, but the acquisition of pathological tissue specimens depends on invasive operations and there are many problems. At present, the application of more advanced functional CT imaging technology to non-invasively assess the pathological behavior of lung cancer before surgery has become a hot research topic. This article reviews the general principles of functional CT imaging and its application in evaluating the pathological behavior of lung cancer.