Abstract: In recent years, cross-infections and even outbreaks of hospital-associated infections caused by residual microorganisms in endoscopes have occurred frequently, attracting widespread attention. However, there has been limited research on the reprocessing and monitoring of endoscopic accessories, particularly valves. Even after routine or high-level cleaning and disinfection, endoscopic valves may still exhibit varying degrees of microorganism contamination. This paper reviews and summarizes the current status and causes of endoscopic valve contamination both domestically and internationally, referencing relevant guidelines and clinical practice research, to provide references for improving the quality of endoscopic valve monitoring, ensuring effective reprocessing, and safeguarding the medical quality and safety associated with endoscopic diagnosis and treatment.