Objective: To analyze the clinical characteristics, drug resistance and risk factors of acute and severe pneumonia caused by a multidrug-resistant Acinetobacter baumannii infection. Methods: From October 2018 to October 2019, 86 patients from the emergency intensive care unit in our hospital suffering from multidrug-resistant Acinetobacter baumannii pneumonia were recruited as the observation group. During the same period, 232 patients admitted to the emergency intensive care unit without infection, or with an Acinetobacter baumannii definite rate alone or contaminated, were selected as the control group. The clinical characteristics of acute and severe pneumonia caused by multidrug-resistant Acinetobacter baumannii were recorded; the bacterias sensitivity to antibiotics was determined using the VITEK-32 automatic bacterial identification instrument. Data was then analyzed using logistic regression. Results: The observation group differed significantly from the control group in terms of older age, longer length of hospital stay, higher incidence of in-hospital mortality and higher APACHE II score (P<0.05). The 86 cases of multidrug-resistant Acinetobacter baumannii had a resistance rate of more than 70% to commonly used antibacterial drugs. Among them, resistance to cefazolin and nitrofurantoin was the highest, both at 97.67%, followed by ampicillin at 91.86% and cefotetan at 89.53%; Acinetobacter baumannii was most sensitive to imipenem, with a sensitivity rate of 60.47%, followed by cefoperazone/sulbactam, with a sensitivity rate of 47.67%. Logistic regression analysis showed that tracheal intubation/incision, use of a drainage tube, urinary tube, gastric tube, arteriovenous catheterization, use of more than three types of antibiotics and use of hormones/immunosuppressive agents, are all risk factors for the development of acute and severe pneumonia from a multidrug-resistant Acinetobacter baumannii infection (P<0.05). Conclusion: Imipenem and beta-lactamase antibacterial inhibitors are recommended as first-line antibiotics for patients with acute and severe pneumonia caused by a multidrug-resistant Acinetobacter baumannii infection. Additionally, practices that prevent nosocomial infection, drug resistance and that reduce relevant risk factors, are recommended to inhibit pneumonia infection.