Objective: To investigate the influencing factors of multi-drug resistant bacterial infections in patients with severe disease and establish a predictive model. Methods: 207 infected patients in our hospital from 2018 to May 2020 were selected for the study, of which 73 carried drug-resistant bacteria. Results: The risk factor network of people infected with multi-drug resistant bacteria is higher than that of people infected with non-multidrug resistant bacteria, and the interaction between risk factors of the former is stronger. Conclusion: Antibiotics must be used appropriately after surgery. When the elderly was abnormal in indicators such as fever and procalcitonin in the ward, they should be considered as high-risk groups of MDRO infection. They need special care and preventive measures.