Objective To investigate the mastery of the management knowledge of patients with atrial fibrillation after coronary artery bypass grafting by cardiac surgeons in Beijing tertiary hospitals, and the practice status and obstacles of following the guidelines for postoperative atrial fibrillation. Methods A convenient sampling method was used to select cardiac surgeons from four tertiary hospitals in Beijing, and a self-designed questionnaire on the management of postoperative atrial fibrillation patients was used. Results A total of 227 valid questionnaires were collected. Only 47.9% of doctors and 12.8% of nurses passed in knowledge, and 31.3% of doctors and 28.5% of nurses passed in behavior. Among them, risk factor assessment, preventive medication, stroke and bleeding risk assessment were the weakest. "Lack of departmental requirements" was identified as a common barrier to healthcare workers' adherence to guidelines. Job title and participation in training were common influencing factors that affected the knowledge and behavior of healthcare workers, and knowledge level was an important factor affecting healthcare worker behavior. Conclusion In order to improve the effect of CABG surgery and improve the quality of postoperative patient management, hospitals should further strengthen the knowledge and skills training of medical staff on the management guidelines of postoperative atrial fibrillation with CABG, formulate relevant systems to ensure the clinical implementation of guidelines.