A sampling system, comprising: a sampling unit, configured for acquiring a tissue sample; a control unit, configured for controlling a working state of the sampling unit and comprising a first adjustment assembly, wherein the first adjustment assembly comprises a first adjustment knob and an actuating string, and the actuating string is rigid; and a connecting tube, assembled to the control unit and having at least one end running through the control unit, and one end of the connecting tube being fixedly assembled to the sampling unit, wherein one end of the actuating string is fixed to the first adjustment knob and an other end of the actuating string is fixed to the sampling unit; and due to the rigidity of the actuating string the sampling unit is controllable to be opened or closed by controlling the first adjustment knob, wherein the sampling unit comprises a sampling sheath, a support portion and a heating member, wherein one end of the sampling sheath inserts into the connecting tube and connected to the connecting tube, and an other end of the sampling sheath is connected to the support portion; the support portion is deformable upon an external force, and the heating member is mounted around the sampling sheath, the one end of the actuating string is fixed to the first adjustment knob and the other end of the actuating string is fixed to the heating member; the actuating string is controllable to move by controlling the first adjustment knob, whereby the heating member is controlled to be opened or closed, which in turn drives the support portion to be opened or closed, the connecting tube comprises a communicating tube, having at least one end extending through the control unit, wherein the one end of the sampling sheath inserts into the communicating tube and is connected to the communicating tube, the communicating tube is provided with a receiving passage and an aperture, wherein the aperture is located in the control unit, the connecting tube further comprises an endoscope tube and an outer sleeve, wherein at least one end of the endoscope tube extends through the control unit, and the outer sleeve is located outside the control unit and has one end assembled to the control unit, the outer sleeve is mounted around the communicating tube, and the communicating tube is mounted around the endoscope tube; characterized in that one end of the endoscope tube is assembled to the sampling sheath, the endoscope tube is movable relative to the control unit, and the sampling system further comprises a balloon unit having a balloon and a metal ring, wherein the balloon is mounted around the metal ring, the metal ring is mounted around the connecting tube, and the balloon unit is located between the sampling unit and the control unit. a sampling unit, configured for acquiring a tissue sample; a control unit, configured for controlling a working state of the sampling unit and comprising a first adjustment assembly, wherein the first adjustment assembly comprises a first adjustment knob and an actuating string, and the actuating string is rigid; and a connecting tube, assembled to the control unit and having at least one end running through the control unit, and one end of the connecting tube being fixedly assembled to the sampling unit, wherein one end of the actuating string is fixed to the first adjustment knob and an other end of the actuating string is fixed to the sampling unit; and due to the rigidity of the actuating string the sampling unit is controllable to be opened or closed by controlling the first adjustment knob, wherein the sampling unit comprises a sampling sheath, a support portion and a heating member, wherein one end of the sampling sheath inserts into the connecting tube and connected to the connecting tube, and an other end of the sampling sheath is connected to the support portion; the support portion is deformable upon an external force, and the heating member is mounted around the sampling sheath, the one end of the actuating string is fixed to the first adjustment knob and the other end of the actuating string is fixed to the heating member; the actuating string is controllable to move by controlling the first adjustment knob, whereby the heating member is controlled to be opened or closed, which in turn drives the support portion to be opened or closed, the connecting tube comprises a communicating tube, having at least one end extending through the control unit, wherein the one end of the sampling sheath inserts into the communicating tube and is connected to the communicating tube, the communicating tube is provided with a receiving passage and an aperture, wherein the aperture is located in the control unit, the connecting tube further comprises an endoscope tube and an outer sleeve, wherein at least one end of the endoscope tube extends through the control unit, and the outer sleeve is located outside the control unit and has one end assembled to the control unit, the outer sleeve is mounted around the communicating tube, and the communicating tube is mounted around the endoscope tube; characterized in that one end of the endoscope tube is assembled to the sampling sheath, the endoscope tube is movable relative to the control unit, and the sampling system further comprises a balloon unit having a balloon and a metal ring, wherein the balloon is mounted around the metal ring, the metal ring is mounted around the connecting tube, and the balloon unit is located between the sampling unit and the control unit.