Objective: To investigate the clinical value of using preoperative nutritional risk screening and support in gastric cancer patients. Methods: In this paper, 70 gastric cancer patients selected from July 2017 to July 2020 treated in our hospital were grouped concerning the lottery method, and the reference group (n=35) used conventional nutritional support, while the experimental group (n=35) used preoperative dietary risk screening and support, comparing the clinical treatment differences between gastric cancer patients in the experimental group and the reference group. Results: After the intervention, IgA, IgM, IgG, serum albumin, complication rate, NRS score, hospitalization time and anal exhaust time of gastric cancer patients in the experimental group were compared with those in the reference group, P<0.05, and there was statistical validation analysis significance between the data indicators. P<0.05 for the comparison of IgA, IgM, IgG, serum albumin after the intervention and pre-intervention for gastric cancer patients in the experimental group and the reference group, with statistical validation analysis significance between the data indicators. Conclusion: Preoperative nutritional risk screening and support is of significant value in gastric cancer patients and can improve patients' nutritional status.