Abstract: Mediastinal infection after cardiac surgery is a severe and common postoperative complication in the field of cardiac surgery, significantly increasing patient mortality and medical resource consumption. Although its incidence has declined with continuous advancements in cardiac surgical techniques, the complex etiology and therapeutic challenges of mediastinal infection still pose significant difficulties in clinical practice.This study focuses on the etiology of mediastinal infection, analyzes its pathogenesis, and, by integrating clinical research and treatment guidelines, primarily discusses the rational selection of antimicrobial agents, combination therapy strategies and recent advances in local anti-infective treatment.