A 5cm lung nodule is clinically known as a mass, and one smaller than 3cm is known as a nodule. 5cm masses have a very high likelihood of malignancy and need to be diagnosed immediately, and if they are malignant, they should be treated surgically if there are surgical indications, and chemotherapy and radiotherapy should be considered at the same time. Lung nodules larger than 8mm need to be taken seriously, and the larger the nodule, the higher the likelihood of malignancy. 5cm lung mass needs to be clarified immediately by pathological examination, etc. If it is clearly malignant, it should be considered for treatment. If it is malignant, anti-cancer treatment should be considered. If the patient is in good physical condition and can tolerate surgery, and at the same time meets the surgical indications of lung tumor, then surgical treatment can be carried out as early as possible. For larger lung cancers, in addition to surgical treatment, chemotherapy, radiotherapy, targeted therapy, etc. can also be carried out to ensure the quality of patient’s survival while prolonging the survival time of the patient as much as possible. Even if malignancy can be ruled out for a 5 cm lung mass, early surgical resection is recommended to avoid malignancy and affecting lung function.