The patient who underwent left lung excision for late stage squamous lung cancer and recurred with blood in sputum three years after surgery may have tumor recurrence and should go to the hospital in time to improve relevant laboratory tests. For some patients with postoperative recurrence, it is necessary to improve relevant auxiliary tests to clarify whether there is any metastasis in other parts of the body. If there is a single recurrence, surgery can be considered to remove the metastatic foci of the tumor; if the patient is unable to tolerate the surgery or has multiple metastases that are not suitable for surgery, chemotherapy, radiotherapy and targeted drug therapy can be chosen to alleviate the patient’s pain and prolong the survival period. If patients have blood in sputum for three years after surgery, they should build up confidence and take active treatment. They need to go to the hospital to improve chest CT, head MRI, bone scan, abdominal ultrasound, tumor markers and other examinations, and standardize treatment under the guidance of doctors to control tumor progression.