Slight thickening of pleura after lung cancer surgery is not necessarily a sign of recurrence, but may also be a thickening of pleura caused by inflammatory hyperplasia due to surgical trauma. After lung cancer surgery, inflammatory exudation occurs in lung mucosa due to surgical injury, and this exudate can stimulate pleura to proliferate, thus leading to slightly thickened pleura on imaging, and this kind of pleural lesion caused by inflammatory proliferation is usually asymptomatic in clinic, and it does not need to be given special treatment. Thickening of pleura after lung cancer surgery can not completely exclude the possibility of recurrent pleural metastasis. Generally, thickening caused by pleural metastasis will often lead to chest pain, cough and other symptoms, which need to seek medical treatment in time to clarify the cause and give anti-tumor treatment in time.