Abstract: A tissue cutter includes a tissue cutting stent and a first reefing thread. The tissue cutting stent is expandable in a radial direction. The expanded tissue cutting stent is loudspeaker-shaped gradually opening from a proximal end to a distal end, and a loudspeaker-shaped accommodating space is formed inside the expanded tissue cutting stent. The tissue cutting stent is provided with a plurality of first threading holes at the distal end, and the plurality of first threading holes is arranged along a circumferential direction of the tissue cutting stent. The first reefing thread passes through the plurality of first threading holes. The first reefing thread has opposite first and second ends. The first end is secured to a starting threading hole in the plurality of first threading holes.