The invention discloses an in-vitro bulk tissue segmentation and collection device under an endoscope, and belongs to the field of surgical instruments, the device comprises a telescopic baffle, a hollow pipeline, a handle, a driving component, a negative pressure component and a collection box, the telescopic baffle is arranged at the front end of the hollow pipeline, the collection box is detachably arranged at the tail end of the hollow pipeline, the handle is arranged on one side of the hollow pipeline, and the driving component is arranged on the other side of the hollow pipeline. The driving component and the negative pressure component are arranged in the handle, the driving component is connected with the telescopic baffle, a cutting blade is arranged at the front end of the hollow pipeline, and the air suction end of the negative pressure component is communicated with the collecting box. The telescopic baffle is driven by the driving component to be attached to the cutting blade, large tissue blocks are rapidly cut into small cylindrical blocks, meanwhile, the small tissue blocks can be collected into the collecting box in a centralized mode after passing through the hollow pipeline, collection is convenient, through the cutting mode that the telescopic baffle is attached to the cutting blade, wounds of a patient are not obviously increased, the operation time can be shortened, and the operation efficiency is improved. And the increased infection probability caused by wound enlargement is avoided.