Lung squamous carcinoma stage 1a3 is T1c in T-staging, N0 in N-staging and M0 in M-staging. Lung cancer can be divided into two main categories, namely small cell lung cancer and non-small cell lung cancer, in which non-small cell lung cancer is further divided into squamous carcinoma, adenocarcinoma, large cell carcinoma, adenosquamous carcinoma and so on. The staging of squamous lung cancer is of great significance for treatment, diagnosis, etc. According to the eighth edition of TNM staging of lung cancer, stage 1a3 of squamous lung cancer refers to stage N0 in N staging, i.e., no regional lymph node metastasis, stage M0 in M staging, i.e., no distant metastasis, stage T1c in T staging, and the maximum diameter of the tumor in stage T1c is >2 cm and ≤3 cm. In the subgroup tumor diameter 2 cm < T1c ≤ 3 cm. Once the pathologic type of lung squamous carcinoma is diagnosed it should be treated promptly.