Inclusion Criteria:  At least 4 operators were included in this study, and the operating years of colonoscopy were ≥ 5 years, and the number of independent operating cases was ≥ 3000.  Subjects who meet all of the following specific criteria will be considered for participation in the study:  Male or female with age ≥ 45 years inclusive; Able to read, understand and sign informed consent; The investigator believes that the subjects can understand the process of the clinical study, are willing and able to complete all study procedures and follow-up visits, and cooperate with the study procedures.  Exclusion Criteria:  Subjects who meet any of the following specific criteria will be refused to participate in the study:  have a history of drug or alcohol abuse or psychological disorders within the last 5 years; Pregnant or lactating women; Patients with known multiple polyp syndrome; patients with known inflammatory bowel disease; known intestinal stenosis or space-occupying tumor; known colon obstruction or perforation; patients with a history of colorectal surgery; Patients with previous history of allergy to pre-used spasmolysis; Unable to perform biopsy and polyp removal due to coagulation disorders or oral anticoagulants; High risk diseases or other special conditions that the investigator considers the subject unsuitable for participation in the clinical trial.