Disclosed is a mucosa staining system, wherein a first staining solution bottle (1) is connected to the first port of a first tee joint (5) through a first pipeline (3), and the second port of the first tee joint (5) is connected to a second staining solution bottle (2) or a flushing bottle (6) through a second pipeline (4), a pump line (7) is connected to the third port of the first tee joint (5), the pump line (7) is installed on a first power device (8), and the pump line (7) is connected to a washing pipe (9) and/or a spray pipe (10), and a first conversion device (11) is connected between the first pipeline (3) and the second pipeline (4). The mucosa staining system integrates the functions of washing and cleaning and staining of the gastrointestinal mucosa into one, and can realize the quick conversion between these two functions, has multiple modes available, can improve the diagnosis and treatment efficiency and comfortability for patients with a gastrointestinal endoscope, and can help reduce the occ
