Microbiological monitoring should be carried out quarterly for sterilized endoscopes, and the method of rotation and sampling should be adopted for monitoring. Sampling inspection shall be conducted at a rate of 25% each time. If there are less than or equal to 5 endoscopes, all of them shall be monitored each time. If there are more than 5 endoscopes, the number of each monitoring shall not be less than 5. Test method: after cleaning and disinfecting the endoscope, 50 ml eluent containing corresponding neutralizer was extracted with sterile syringe, and then the endoscopy pipeline was flushed from the biopsy port and collected in full for inspection. It is suggested to adopt the membrane filtration method for laboratory test, and the qualification standard is: the total number of colonies ≤ 20cfu / piece.