Carbapenem-resistant Acinetobacter baumannii (CRAB) infection is associated with reduced early postoperative survival among liver transplant recipients with acute-on-chronic liver failure (ACLF). We report the first case at our center in which Sulbactam-Durlobactam (SUL-DUR) was successfully used to treat a CRAB pulmonary infection patient with ACLF following liver transplantation. After initiating SUL-DUR therapy, next-generation sequencing (NGS) demonstrated a progressive decline in CRAB sequence counts. By day 4, CRAB-specific PCR of bronchoalveolar lavage fluid (BALF) returned negative, and CRAB was undetectable in subsequent BALF cultures. The treatment demonstrated favorable clinical efficacy, with notable radiological improvement and rapid microbial eradication. SUL-DUR not only rapidly controlled the progression of CRAB-induced pulmonary infection, but also facilitated the early initiation of immunosuppressive therapy. Subsequent in vitro antimicrobial susceptibility testing revealed synergy between SUL-DUR and cefepime, though no such synergy was observed with imipenem. This case underscores the promising role of SUL-DUR in managing post-transplant CRAB pneumonia, especially in high-risk patients with acute-on-chronic liver failure. Our findings may provide a valuable reference for optimizing therapeutic strategies in similar clinical cases.