Objective To explore the effect of Fuzheng Yangyin Prescription on immune function and quality of life of postoperative chemotherapy patients with gastrointestinal tumors. Methods A total of 64 patients with deficiency of Qi and Yin after chemotherapy of gastrointestinal tumors treated in Changshu No.1 People′s Hospital from August 2018 to December 2019 were selected as the research objects. They were divided into control group and Fuzheng Yangyin Prescription group according to random number table method, with 32 cases in each group. The control group was treated with first-line chemotherapy, Fuzheng Yangyin Prescription group was treated with Fuzheng Yangyin Prescription on the basis of the control group.The changes of Karnofsky performance score(KPS),traditional Chinese medicine syndrome score and cellular immune indexes were compared between the two groups before and after treatment. Results There was no significant difference in CD3+ between the two groups before treatment (P＞0.05). After treatment, CD3+ in the two groups were higher than those before treatment, and the CD3+ in the Fuzheng Yangyin Prescription group was higher than that in the control group, and the differences were statistically significant (P＜0.05). There was no significant difference in CD4+between the two groups before treatment (P＞0.05). After treatment, CD4+in the two groups were lower than those before treatment, and the CD4+in the Fuzheng Yangyin Prescription group was lower than that in the control group, the differences were statistically significant (P＜0.05). There was no significant difference in CD4+/CD8+ratio between the two groups before treatment (P＞0.05). After treatment, the CD4+/CD8+ ratios of the two groups were higher than those before treatment, and the CD4+/CD8+ ratio in the Fuzheng Yangyin Prescription group was higher than that in the control group, the differences were statistically significant (P＜0.05). There was no significant difference in KPS score between the two groups before treatment (P＞0.05). After treatment, the KPS scores of the two groups were higher than those before treatment, the KPS score of Fuzheng Yangyin Prescription was higher than that of the control group,the differences were statistically significant (P ＜0.05). There was no significant difference in traditional Chi nese medicine syndrome score between the two groups before treatment (P＞0.05). After treatment, the traditional Chinese medicine syndrome scores of the two groups were lower than those before treatment, the traditional Chinese medicine syndrome score of the Fuzheng Yangyin Prescription group was lower than that of the control group, the differences were statistically significant (P＜0.05). Conclusion Fuzheng Yangyin Prescription can improve the immune function and quality of life of patients with gastrointestinal tumors after chemotherapy.