Neoadjuvant chemotherapy for lung cancer is defined as cytoreductive therapy prior to local treatment. It is another form of combining surgery and chemotherapy, and compared to adjuvant chemotherapy, neoadjuvant chemotherapy is the advancement of systemic therapy to precede local therapy. The potential advantages of neoadjuvant are: early killing of systemic micrometastases through intact vessels supplemented with chemotherapeutic agents. Reducing local tumor load, decreasing tumor stage, increasing the likelihood of surgical resection, and improving the rate of complete surgical resection. To guide the correct postoperative chemotherapy by evaluating the effectiveness of chemotherapy in vivo; to prevent intraoperative tumor dissemination, avoid postoperative tumor recurrence and metastasis, and prolong survival; and to increase patient compliance and tolerability. Roch et al. sued many retrospective and prospective studies have confirmed that preoperative chemotherapy for NSCLC is safe and well tolerated by patients. The application of neoadjuvant chemotherapy in patients with stage IIIA NSCLC is beneficial in increasing surgical resection rates and improving survival. In a prospective study, the Thiers randomly divided stage IIIA NSCLC cases into neoadjuvant chemotherapy and surgery-only groups. The neoadjuvant chemotherapy group was treated with three cycles of cyclophosphamide, etoposide, and cisplatin regimens preoperatively, and the median survival of the two groups was found to be 64 and 11 months, respectively, and the 3-year survival rates were 56% and 15%, respectively, with statistically significant differences between the two groups. A group of 373 patients with operable stage I-IIIA were randomly divided into those who received 2 cycles of mitomycin, isocyclophosphamide, and cisplatin regimen chemotherapy surgery group and surgery alone group, grouped as 187 and 186 patients, the preoperative chemotherapy group achieved clinical partial remission and pathological complete remission after surgery, and then received 2 cycles of treatment after surgery, the median survival of the two groups were 37 and 26 months, respectively. The difference in survival increased from 8.3% at 1 year to 8.6% at 4 years, with statistically significant beneficiaries limited to patients with stage N0.N1. However, this study found that 90% of subjects received the planned treatment dose, improving compliance with good treatment with neoadjuvant chemotherapy.Rosell et al. prospectively randomized 60 stage IIIA cases in which the neoadjuvant chemotherapy group received 3 cycles of regimen chemotherapy with mitomycin, isocyclophosphamide, and cisplatin. The control group underwent direct surgery, resulting in a median survival of 26 and 8 months in the two groups, respectively, and a 3-year survival rate of 30% and 0, respectively, with statistically significant differences.