Atissue cutter, comprising a tissue cutting stent (1, 1', 1") being expandable in a radial direction and a first reefing thread; the expanded tissue cutting stent (1, 1', 1") being loudspeaker-shaped gradually opening from a proximal end to a distal end, and a loudspeaker-shaped accommodating space being formed inside the expanded tissue cutting stent (1, 1', 1"), the tissue cutting stent (1, 1', 1") provided with a plurality of first threading holes (50, 50') at the distal end, the plurality of first threading holes (50, 50') arranged along a circumferential direction of the tissue cutting stent (1, 1', 1"); and the first reefing thread passing through the plurality of first threading holes (50, 50'), the first reefing thread having opposite first and second ends, the first end secured to a starting threading hole in the plurality of first threading holes (50, 50'); wherein the tissue cutting stent (1, 1', 1") comprises a fixed part, a support part (20, 20', 20") and an expansion part (30, 30', 30"), the fixed part, the support part (20, 20', 20") and the expansion part (30, 30', 30") connected sequentially along the axial direction of the tissue cutting stent (1, 1', 1"), from the proximal end to the distal end, the plurality of first threading holes (50, 50') provided on the expansion part (30, 30', 30"), the support part (20, 20', 20") and the expansion part (30, 30', 30") being expandable along the radial direction to form the accommodating space (20, 20', 20"); and characterised in that the support part (20, 20', 20") is provided with a plurality of second threading holes, the plurality of second threading holes arranged along the circumferential direction of the tissue cutting stent (1, 1', 1"), and the tissue cutter further comprises a second reefing thread, the second reefing thread passing through the plurality of second threading holes. the expanded tissue cutting stent (1, 1', 1") being loudspeaker-shaped gradually opening from a proximal end to a distal end, and a loudspeaker-shaped accommodating space being formed inside the expanded tissue cutting stent (1, 1', 1"), the tissue cutting stent (1, 1', 1") provided with a plurality of first threading holes (50, 50') at the distal end, the plurality of first threading holes (50, 50') arranged along a circumferential direction of the tissue cutting stent (1, 1', 1"); and the first reefing thread passing through the plurality of first threading holes (50, 50'), the first reefing thread having opposite first and second ends, the first end secured to a starting threading hole in the plurality of first threading holes (50, 50'); wherein the tissue cutting stent (1, 1', 1") comprises a fixed part, a support part (20, 20', 20") and an expansion part (30, 30', 30"), the fixed part, the support part (20, 20', 20") and the expansion part (30, 30', 30") connected sequentially along the axial direction of the tissue cutting stent (1, 1', 1"), from the proximal end to the distal end, the plurality of first threading holes (50, 50') provided on the expansion part (30, 30', 30"), the support part (20, 20', 20") and the expansion part (30, 30', 30") being expandable along the radial direction to form the accommodating space (20, 20', 20"); and characterised in that the support part (20, 20', 20") is provided with a plurality of second threading holes, the plurality of second threading holes arranged along the circumferential direction of the tissue cutting stent (1, 1', 1"), and the tissue cutter further comprises a second reefing thread, the second reefing thread passing through the plurality of second threading holes.