The invention relates to the field of medical instruments, and particularly discloses a high-definition colonoscopy system. The high definition colonoscopy system comprises a main controller provided with a displayer. The high-definition colonoscopy system is characterized in that the main controller is connected with an endoscope through a data line, the endoscope comprises a handle with the end provided with a microscope, the front end of the lens of the microscope is connected with a connecting pipe through a bayonet, the bayonet is internally provided with an optical fiber circuit connected with the main controller, and the connecting pipe is sleeved with a disposable telescope. The high-definition colonoscopy system is simple in structure, convenient to use, reasonable in design and flexible in application, and has the functions of freezing, playing back, collecting, storing, measuring focuses, the lesion states of the interior the enteric cavity can be clearly detected, the result is accurate and visual, and the high-definition colonoscopy system is suitable for being widely applied to anus and anal tube disease detection.