Objective: To explore the causes of enteral nutritional diarrhea in ICU patients, and to provide a basis for the formulation of nursing countermeasures. Methods: 116 hospitalized patients with ICU were selected and 62 cases were divided into diarrhea group and 54 cases of non-diarrhea group. The severity, defecation and drug use of two groups of patients were investigated, and univariate and multivariate Logistic regression analysis was performed to find out the cause of enteral nutrition diarrhea. Results: Logistic regression analysis showed that age, application of antibiotics, gastric dynamic agents, antacids, potassium and probiotics were associated with enteral nutritional diarrhea（P<0.05）. The application of probiotics was a protective factor in patients with ICU enteral nutrition diarrhea. The OR value was 0.865. Age, antibiotics, gastric dynamic agents, antacids and potassium agents were risk factors for enteral nutritional diarrhea, and OR values were all greater than 1. Conclusion: Age, application of antibiotics, gastric dynamic agents, antacids and potassium agents are the main risk factors for ICU enteral nutrition diarrhea, and clinical risk factors should be avoided to improve the tolerance of nutrition support.