Objective To explore the effect of nutritional intervention in case management on patients after radical gastrectomy for gastric cancer. Method Using real data studies, patients were divided into two groups according to the chronological order of surgery. In November 2017 to October 2018 as control group, 173 cases of patients with gastric cancer radical, control group patients during hospitalization, complete all screening, assessment, treatment, according to the situation of gastric bowel function, by the competent physicians, nurses, dietitians daily rounds to guide patients to eat, after hospital discharge, by the competent nurses for patients with gastric cancer surgery patients diet instruction manual, follow⁃up was completed at 1, 2, 3 and 6 months postoperatively. 166 patients in the experimental group underwent radical gastritis from November 2018 to October 2019. Patients in the experimental group received the same guidance during hospitalization, and were followed up by special case managers (including patients and their families) after discharge to understand the nutritional status of patients at home and give guidance. Nutritional risk, incidence of malnutrition, hemoglobin, serum total protein, prealbumin, albumin, weight gain, triceps dermal fold thickness, right hand grip strength and incidence of complications were compared between 2 groups. Result 166 patients completed the study. Without considering the effect of time accumulation on the results, nutrition intervention was implemented in case management. The nutritional risk and malnutrition incidence of the experimental group were lower than those of the control group at different periods of the investigation. Nutritional risk, good nutrition, hemoglobin, serum total protein, prealbumin, albumin, body weight gain and triceps skin fold thickness of the experimental group were significantly different from those of the control group (P < 0.05). Conclusion Nutritional intervention in case management of patients undergoing radical gastrectomy for gastric cancer is helpful to improve patients' wrong dietary concept and nutritional status.