Objective To investigate an outbreak of suspected carbapenem-resistant Acinetobacter baumannii(CRAB) infection in the emergency intensive care unit (EICU) of a hospital, and evaluate the effect of intervention measures. Methods Epidemiological investigation was carried out on 6 CRAB patients with detection of CRAB and were warned by healthcare-associated infection (HAI) monitoring software in EICU of a hospital from February 9 to 14, 2022, environmental specimens that may be contaminated were performed microbial sampling, culture, identification and antimicrobial susceptibility testing, and comprehensive control measures were taken, detection of CRAB in patients and environment after intervention was continuously monitored. Results Among 6 patients with CRAB, 4 had HAI and 2 had colonization.Cases 1, 3, 4 and 5 originated from CRAB, except intermediately resistant to tegacyclin and levofloxacin, they were all resistant other antimicrobial agents and had the same resistance spectrum.Environmental hygiene monitoring showed that the detection rate of CRAB was 20.00%(40/200) in the outbreak, CRAB was detected from bed units, equipment and instruments, health care workers and cleaners, antimicrobial susceptibility results were consistent with the strains from patients.By improving the implementation rate of contact isolation, strictly implementing hand hygiene, taking targeted intervention measures such as joint prevention and control training on infection and supervision of multiple departments in the hospital, CRAB target monitoring was carried out in this department for three months, results showed that CRAB infection rate from March to May were 25.00%(12/48), 18.75%(9/48) and 12.50%(6/48) respectively, showing a downward trend (χ_trend²=56.00, P < 0.05);continuous environmental hygiene sampling didn't isolate CRAB, and this event was effectively controlled. Conclusion Inadequate implementation of contact isolation, nonstandard use of antimicrobial agents, inadequate implementation of hand hygiene and incomplete environmental cleaning may be the main causes for the outbreak of CRAB, timely identification, investigation and targeted prevention and control strategies are the key mea-sures to effectively control the infection of multidrug-resistant organism.