A modified screening tool for the asscssrllenl of malnutrition in paediatrics (STAMP) was applied to assess and screen the nutritional risk of hospitalized children and observe the effects of nutritional support therapy on clinical outcomes of children with high nutritional risk. Methods: A total of 1296 children in pediatric medicine and pediatric general surgery were selected consecutively, and 379 children at high nutritional risk with STAMP score ≥4 were randomly observed for nutritional support treatment, and the effects of nutritional treatment on clinical outcomes of children at high nutritional risk were statistically analyzed in groups. Results: Enteral nutrition (EN) had the lowest utilization rate (7.57%) but the lowest cost, parenteral nutrition (PN) had the highest utilization rate (12.17%), and the combination of EN+PN had the highest cost, and the cost difference between the three nutrition treatment modalities was statistically significant (P<0.05); the rate of nosocomial infections in children treated with nutritional support was significantly lower than in children without nutritional treatment (< span="">P=0.008); nutritional support significantly reduced the mean cost of diagnosing and treating infectious complications (t=3.515,P=0.001), and although it reduced the cost of antibiotics in patients with infectious complications, it was not statistically significant (P>0.05); the PN group The average daily hospitalization cost of nutritional support was higher than that of the group without nutritional support and the difference was statistically significant (P=0.006); nutritional support did not increase the total hospitalization cost and the average daily hospitalization cost, and the differences were not statistically significant; nutritional support reduced the length of hospitalization to different degrees in all groups, but there was no significant difference; the length of hospitalization of children with complications of infection was significantly longer (P=0.000), and for children with The total cost of hospitalization was significantly lower for children with complications of infection (P=0.004) and the length of hospitalization was significantly shorter for children without nutritional support (P=0.016). The best cost-effectiveness ratio was achieved with enteral nutrition support treatment. Conclusion The STAMP score, a modified screening tool for pediatric malnutrition assessment, is simple and convenient to use and can effectively evaluate the nutritional risk of hospitalized children; there are differences in costs depending on the mode of nutritional support; reasonable nutritional interventions for children with high nutritional risk can effectively reduce the occurrence of infectious complications, lower total hospital costs and shorten the length of stay, and nutritional support does not increase the financial burden of patients and can effectively improve Nutritional support does not increase the financial burden of patients and can effectively improve the clinical outcome of patients, especially for patients with infectious complications.