Lung adenocarcinoma PL0 is the term for the grade of pleural invasion of lung adenocarcinoma, which indicates that the tumor is confined to the subpleural lung parenchyma or invades the connective tissue of the meningeal surface but has not yet invaded the elastic lamina. There are four levels of pleural invasion, PL0, PL1, PL2 and PL3, except PL0, PL1 indicates that the tumor invades beyond the elastic lamina, PL2 indicates that the tumor invasion reaches the surface of the pleura, and PL3 indicates that the tumor invades the wall pleura. Lung adenocarcinoma is a serious threat to people’s health, and early diagnosis, accurate staging, and precise individualized treatment are crucial to patient prognosis. Therefore, accurate judgment of the invasion of the pleura of the dirty layer is crucial for the formulation of postoperative treatment plan and prognosis of patients, which is also the significance of the grade grading of pleural invasion in lung adenocarcinoma.