CRYOABLATION NEEDLE HAVING J-T SLOT SLEEVE

A cryoablation needle having a J-T slot sleeve (18), comprising a vacuum wall (2), a J-T slot (1), and a J-T slot sleeve (18). The vacuum wall (2) comprises a needle rod (21) and an inner tube (22); a far end of the needle rod (21) is provided with a needle tip (211); the inner tube (22) penetrates through the needle rod (21); an interlayer is formed between the inner tube (22) and the needle rod (21); a first preset distance exists between a far end of the inner tube (22) and the far end of the needle rod (21); the J-T slot (1) and the J-T slot sleeve (18) are sleeved in the inner tube (22); the J-T slot sleeve (18) is sleeved at a far end of the J-T slot (1); the J-T slot sleeve (18) can move relative to the J-T slot (1); in areas in which the vacuum wall (2) is distributed in the axis direction of the vacuum wall, an area where the interlayer is located is a vacuum heat insulation area (26), and an area where the first preset distance is located is a target area (25); the far end of the J-T slot sleeve (18) at least comprises two adjusting positions relative to the vacuum wall (2); a first adjusting position is located in the target area (25); and a second adjusting position is located in the vacuum heat insulation area (26). The far end of the J-T slot sleeve (18) is switched between the at least two adjusting positions, such that the cooling rate is greatly accelerated.