To compare the clinical efficacy and immune function of oxitinib and Pemetrexed+carboplatin in the treatment of advanced non squamous non-small cell lung cancer. Methods From December 2016 to December 2020, 168 patients with advanced non squamous non-small cell lung cancer in our hospital were selected. According to the random number table method, the patients were divided into group A(56 cases), Pemetrexed+carboplatin group(56 cases)，and group B(56 cases). Group A was only treated with oxitinib, group B was only treated with pemetrexed+ carboplatin,and the combined group was treated with oxitinib combined with pemetrexed+carboplatin. Results The disease control rate of the combined group is higher than that of group A and group B(P＜0.05). Compared with before treatment, the levels of CD3+, CD4+, CD4+/CD8+ in the three groups were significantly increased(P＜0.05), and the level of CD8+ was decreased(P＜0.05). The improvement degree of the above indexes in the combination group was significantly different from that in the a and B groups(P＜0.05). There was no significant difference in the total incidence of adverse reactions between group A and group B(P＞0.05). Conclusion The treatment of advanced non squamous non-small cell lung cancer patients with oxalitinib combined with Pemetrexed+carboplatin can achieve good clinical effect, can improve the immune function of patients, the curative effect is safe and reliable, and can bePemetrexed+carboplatin in clinical.