To observe the clinical effect and safety of Shenling Baizhu Powder（参苓白术散）combined with FOLFOX4 regimen chemotherapy in the treatment of advanced colorectal cancer（CRC）.

One hundred and thirty-two patients with advanced CRC admitted to Nanyang First People's Hospital from June 2021 to June 2024 were selected as research subjects and randomly divided into treatment group（66 cases）and control group（66 cases）. The control group used the FOLFOX4 chemotherapy regimen，with 2 weeks as one cycle，and a total of 6 cycles of chemotherapy. The treatment group was treated with Shenling Baizhu Powder on the basis of the control group. It was decocted in water and taken once in the morning and once in the evening，with warm intake after meals. One dose was taken daily for 12 consecutive weeks. The clinical efficacy of the two groups was compared after 12 weeks of treatment. The traditional Chinese medicine syndrome scores，tumor marker expression levels and immune function of the two groups were compared before and after treatment. The occurrence of adverse reactions during the treatment of the two groups was recorded.

The disease control rate（DCR）of the treatment group（81.82%，54/66）was higher than that（60.61%，40/66）of the control group（χ²=7.243，P<0.05）. After 12 weeks of treatment，the TCM syndrome scores，serum levels of carcinoembryonic antigen（CEA）and carbohydrate antigen-199（CA-199）in the treatment group［（12.66±3.29）points，（13.44±3.18）μg·L^-1，（32.23±4.17）U·mL^-1］were lower than those of the control group group［（16.84±3.87）points，（17.68±3.89）μg·L^-1，（40.49±4.54）U·ml^-1］（t=6.685，6.856，10.886，P<0.05）. The values of CD3⁺，CD4⁺ and CD4⁺/CD8⁺ in the treatment group［（66.29±8.33）%，（41.72±4.88）%，1.86±0.47］ were all higher than those in the control group［（61.57±7.16）%，（38.54±4.21）%，1.69±0.39］（t=3.491，4.008，2.261，P<0.05）. During the treatment period，the incidence of neurotoxicity，gastrointestinal discom fort，hematuria，thrombocytopenia and total adverse reactions in the treatment group were lower than those in the control group（x²=3.895，4.117，3.895，5.114，24.877，P<0.05）.

Shenling Baizhu Powder combined with FOLFOX4 can effectively alleviate the clinical symptoms of patients with advanced CRC，improve the patients’ immune function，and reduce the expression levels of serum tumor markers. It has significant clinical efficacy and good safety.