Objective To investigate the effect of nutritional management during postoperative chemotherapy in children with neuroblastoma. Method A total of 88 neuroblastoma patients treated in Hematology Oncology Center, Beijing Children’s Hospital, Capital Medical University from November 2019 to March 2021 after chemotherapy were randomly divided into control group and observation group, 44 patients each. The control group received routine diet nursing, and the observation group received whole⁃course nutrition management on the basis of routine nursing. Centralized management in the hospital and Wechat group management established outside the hospital lasted for 3 months. Nutritional indicators and adverse reactions of patients in the two groups during postoperative chemotherapy were compared. Result The absolute values of serum prealbumin [ (169.66±30.46) mg/L vs (158.68±19.18) mg/L], serum albumin [(44.86±3.72) mg/L vs (42.90±4.47) mg/L], hemoglobin [(108.23±14.16) g/L vs (102.36±11.37) mg/L] and lymphocytes [0.91 (0.64, 1.11)×109 vs 0.68 (0.42, 1.02)×109] in the observation group were higher than those in the control group (P<0.05); the weight gain was higher than that of the control group, but there was no significant difference (P=0.238). The incidence of adverse reactions, such as malnutrition risk screening score [(5.23±1.51）vs（6.05±1.90）], infection [10 (22.7%) vs 19 (43.2%)], anorexia [15 (34.1%) vs 29 (65.9%)] and reduced chemotherapy intensity [1 (2.3%) vs 6 (13.6%)] were lower in the observation group than in the control group. The difference was statistically significant (P<0.05). The incidence of malnutrition and diarrhea was lower than that of control group (P>0.05). Conclusion Nutritional management can effectively improve the nutritional status of patients after tumor operation and reduce the incidence of malnutrition and adverse reactions of chemotherapy.