The present invention discloses a tissue closure device, a tissue closure assembly and a medical instrument. The tissue closure device comprises a base, a pressure plate cooperating with the base, and a staple pushing sheet. The pressure plate is rotatable relatively to the base. The tissue closure device further comprises a staple accommodating portion which is arranged at the distal end of the base and configured to accommodate a closure staple. The staple pushing sheet and the staple accommodating portion are configured to cooperatively drive the closure staple in the staple accommodating portion to deform. In the present invention, a bundled pouch with a gathered center is formed through the tissue closure device, so that risks of stoma fistula arising from subsequent anastomosis through a circular stapler are reduced； and the surgery cost is reduced.
