An adjustable cryoablation needle, comprising a needle rod, a distal-segment heat-insulated tube and a gas inlet structure penetrating the needle rod wherein the distal-segment heat-insulated tube is inserted into the needle rod from a proximal end of the needle rod, the distal-segment heat-insulated tube can move relative to the needle rod in the axial direction of the needle rod, the gas inlet structure comprises a first gas inlet tube and a spring-like second gas inlet tube that can be stretched and compressed in the axial direction, a distal of the first gas inlet tube extends to the needle rod, and a proximal end of the first gas inlet tube is connected to the distal end of the second gas inlet tube, wherein, the adjustable cryoablation needle further comprises a proximal-segment heat-insulated tube, and the distal-segment heat-insulated tube is connected to the proximal-segment heat-insulated tube from a distal end of the proximal-segment heat-insulated tube; the needle rod is configured to move relative to the proximal-segment heat-insulated tube in the axial direction of the proximal-segment heat-insulated tube, so as to adjust a first axial distance along the axial direction between the distal end of the proximal-segment heat-insulated tube and the distal end of the needle rod; the distal-segment heat-insulated tube is configured to move relative to the proximal-segment heat-insulated tube in the axial direction of the proximal-segment heat-insulated tube, so as to adjust a second axial distance along the axial direction between the distal end of the distal-segment heat-insulated tube and the distal end of the proximal-segment heat-insulated tube; wherein the length of an effective needle rod segment of the adjustable cryoablation needle changes with the first axial distance; when the length of the effective needle rod segment changes, the distal-segment heat-insulated tube is configured to move relative to the needle rod in the axial direction of the needle rod, so that the length of a targeting region of the adjustable cryoablation needle changes with the difference between the first axial distance and the second axial distance, the position of the first gas inlet tube is fixed relative to the needle rod, the proximal end of the second gas inlet tube is directly or indirectly connected to a gas inlet passage, the position of the gas inlet passage is fixed relative to the proximal-segment heat-insulated tube, and characterized in that the second gas inlet tube is configured to be compressed or stretched in the axial direction when the first axial distance is adjusted. the adjustable cryoablation needle further comprises a proximal-segment heat-insulated tube, and the distal-segment heat-insulated tube is connected to the proximal-segment heat-insulated tube from a distal end of the proximal-segment heat-insulated tube; the needle rod is configured to move relative to the proximal-segment heat-insulated tube in the axial direction of the proximal-segment heat-insulated tube, so as to adjust a first axial distance along the axial direction between the distal end of the proximal-segment heat-insulated tube and the distal end of the needle rod; the distal-segment heat-insulated tube is configured to move relative to the proximal-segment heat-insulated tube in the axial direction of the proximal-segment heat-insulated tube, so as to adjust a second axial distance along the axial direction between the distal end of the distal-segment heat-insulated tube and the distal end of the proximal-segment heat-insulated tube; wherein the length of an effective needle rod segment of the adjustable cryoablation needle changes with the first axial distance; when the length of the effective needle rod segment changes, the distal-segment heat-insulated tube is configured to move relative to the needle rod in the axial direction of the needle rod, so that the length of a targeting region of the adjustable cryoablation needle changes with the difference between the first axial distance and the second axial distance, the position of the first gas inlet tube is fixed relative to the needle rod, the proximal end of the second gas inlet tube is directly or indirectly connected to a gas inlet passage, the position of the gas inlet passage is fixed relative to the proximal-segment heat-insulated tube, and characterized in that the second gas inlet tube is configured to be compressed or stretched in the axial direction when the first axial distance is adjusted.