We report a clinical case of female lung cancer patient with stage IIIC, unresectable cancer. The patient received icotinib followed by aumolertinib neoadjuvant therapy, achieved significant tumor size shrinkage and downstaging to meet resectability criteria....Genetic testing showed EGFR exon 19 deletion mutation. The patient received oral icotinib (125mg, tid) treatment. Following CT review showed the primary lesion was partial response. However, the patient performed clinical and imaging disease progression in June 2021. Further genetic testing showed EGFR exon 19 deletion and acquired T790M mutation. Thus, the patient received oral aumolertinib 110 mg, the primary lesion shrank significantly, achieving PR and clinical stage descended to stage IB...Genetic detection and immunostaining indicated T790M mutation and a positive expression of PD-L1 (TPS =8%). Then she received aumolertinib as postoperative adjuvant therapy. So far, the patient is still in follow-up visits, and no evidence of recurrence or metastasis in relevant examinations. During the whole treatment, excellent tumor remission and favorable safety profile in the perioperative phases was satisfactory.