Objective To explore the application effects of problem-based health education on family nutrition support for patients with gastric cancer after surgery. Methods A total of 84 postoperative gastric cancer patients were randomly divided into the control group（n=42） and the interventional group（n=42）. Patients in the control group received routine care while patients in the experimental group received health education based on problem classification. The problem classification included problem identification,problem summary,problem categorization,and problem solving. After the intervention,the two groups’ dietary health knowledge,nutritional indicators,nutritional scores and incidence of complications were compared. Results The score of diet knowledge in the interventional group was higher than that in control group（P<0.05）. The weight,albumin,prealbumin,transferrin,retinol binding protein,globulin and lymphocyte index in interventional group were all higher than those in the control group. The Nutrition Risk Screening 2002 and Patient-Generated Subjective Global Assessment were improved,and the complication rate was lower than that in control group. All comparisons were statistically different（P<0.05）. Conclusion The health education based on problem classification can significantly improve the level of dietary health knowledge and nutritional indicators of postoperative gastric cancer patients and reduce complication rate.