Abstract： Objective： To observe the effect of Renshen Dahuang Decoction combined with external application with Euodiae Fructus on gastrointestinal function and immune function in patients with advanced gastric cancer. Methods： A total of 79 cases of patients with advanced gastric cancer were selected and divided into the observation group and the control group according to different treatment methods， with 47 and 32 cases in each group respectively. The control group was treated with the external application with Euodiae Fructus based on basic chemotherapy， and the observation group was additionally treated with Renshen Dahuang Decoction based on the treatment of the control group. Clinical effects were evaluated in the two groups. The time of first exhaust，the time of first defecation，the recovery time of borborygmus， the scores of Gastrointestinal Symptom Rating Scale (GSRS)， serum motilin (MTL)， and vasoactive intestinal peptide (VIP) in serum，traditional Chinese medicine (TCM) syndrome scores and T cell subgroup levels were compared between the two groups before and after treatment. The scores of Quality of Life (QOL) at 7，14，and 28 days after treatment and gastrointestinal complications were observed in the two groups. Results：The excellent and good rate of gastrointestinal function recovery in the observation group was significantly higher than that in the control group，the difference being significant (P＜0.05). The time of first exhaust， the time of first defecation， and the recovery time of borborygmus in the observation group were shorter than those in the control group (P＜0.05). After treatment，GSRS scores and MTL levels in the two groups were decreased when compared with those before treatment，VIP levels were increased when compared with those before treatment (P＜0.05)； GSRS scores and MTL levels in the observation group were lower than those in the control group， and the VIP level was higher than that in the control group (P＜0.05). After treatment，TCM syndrome scores in the two groups were lower than those before treatment (P＜0.05)，and the scores in the observation group were lower than those in the control group (P＜0.05). After treatment，the levels of CD3+，CD4+，and CD4+/CD8+ in the two groups were increased when compared with those before treatment，and the levels of CD8+ were decreased when compared with those before treatment (P＜0.05)； the levels of CD3 + ， CD4 + ， and CD4 +/CD8 + in the observation group were higher than those in the control group，and CD8+ level in the observation group was lower than that in the control group (P＜0.05). The QOL scores at 14 and 28 days after treatment in the observation group were higher than those in the control group (P＜0.05). The incidence of gastrointestinal complications in the observation group was lower than that in the control group (P＜0.05). Conclusion： Renshen Dahuang Decoction combined with external application with Euodiae Fructus can effectively improve gastrointestinal function，immune function and quality of life in patients with advanced gastric cancer during chemotherapy.