Due to the special structure and material of the flexible gastrointestinal (GI) endoscopes, it is difficult to reprocess endoscopes. Infections caused by endoscope reprocessing failure often occur. Strict implementation of the guidelines/relevant national standards and manufacturer's instructions is essential to prevent the occurrence of endoscopy-related infections and ensure patient safety. In 2020, ASGE (American Society for Gastrointestinal Endoscopy) released the "multisociety guideline on reprocessing flexible GI endoscopes and accessories". This paper aimed to promote the understanding of the reprocessing process of flexible GI endoscopes by the endoscope decontamination staff, and to provide references for clinical practice.