To evaluate effect of targeted individualized nutrition support on therapeutic effect and safety of patients with severe diseases during hospitalization. All patients were divided into control group and the observation group according to the time of admission. All enrolled patients received symptomatic treatment and intensive care. The control group received only basic nutrition support. There was no significant difference in NRS2002 score between the two groups at admission. Before intervention, there were no significant differences of total serum protein, serum albumin, hemoglobin content, liver and kidney functions and immune indexes between both groups. After intervention, the total serum protein, serum albumin and hemoglobin content of observation group was significantly higher than those of control group. The incidence of adverse events and complications of observation group was significantly lower than control group during hospitalization. The targeted individualized nutrition support could improve nutritional status of patients with severe surgical diseases during hospitalization.