A disposable safe vein transfusion puncture needle, comprising a needle head, a needle base, a needle sheath, sleeved on the needle head; and a hose, communicated with the needle base, a plurality of slidable components (1, 2); and a plurality of limiting mechanisms, wherein, the needle base is in a tubular shape, with one end stationary and communicated with the needle head and the other end connected to the hose; each of the slidable components (1, 2) is in a tubular shape and has two open ends, the plurality of slidable components (1, 2) are sleeved on one another, the innermost slidable component is movably sleeved onto the needle base, and a sum of lengths of the plurality of slidable components (1, 2) in a moving direction is longer than the length of the needle head; the limiting mechanisms are disposed on the plurality of slidable components (1, 2) as well as on the needle base and adapted for securing the innermost slidable component to the needle base as well as securing the plurality of slidable components (1, 2) to one another when the plurality of slidable components (1, 2) slide to completely shield the needle head, the disposable safe vein transfusion puncture needle comprises a first slidable component movably sleeved on the needle base and a second slidable component movably sleeved on the first slidable component, characterized in that the limiting mechanisms comprise two elastic fasteners (13, 21) and four grooves (31, 32, 11, 12), one of the elastic fasteners is disposed on the first slidable component, and the other elastic fastener is disposed on the second slidable component; two of the grooves (31, 32) are disposed on the needle base, and the other two grooves (11, 12) are circumferentially disposed on an exterior wall of the first slidable component; the elastic fasteners (13, 21) and the grooves (31, 32, 11, 12) are adapted for engaging with each other when the first slidable component and the second slidable component slide to completely shield the needle head or when the needle head is completely exposed, so as to limit the movement of the first slidable component and the second slidable component, one end of the second slidable component close to the hose has a smooth projection portion circumferentially disposed thereon. a needle head, a needle base, a needle sheath, sleeved on the needle head; and a hose, communicated with the needle base, a plurality of slidable components (1, 2); and a plurality of limiting mechanisms, wherein, the needle base is in a tubular shape, with one end stationary and communicated with the needle head and the other end connected to the hose; each of the slidable components (1, 2) is in a tubular shape and has two open ends, the plurality of slidable components (1, 2) are sleeved on one another, the innermost slidable component is movably sleeved onto the needle base, and a sum of lengths of the plurality of slidable components (1, 2) in a moving direction is longer than the length of the needle head; the limiting mechanisms are disposed on the plurality of slidable components (1, 2) as well as on the needle base and adapted for securing the innermost slidable component to the needle base as well as securing the plurality of slidable components (1, 2) to one another when the plurality of slidable components (1, 2) slide to completely shield the needle head, the disposable safe vein transfusion puncture needle comprises a first slidable component movably sleeved on the needle base and a second slidable component movably sleeved on the first slidable component, characterized in that the limiting mechanisms comprise two elastic fasteners (13, 21) and four grooves (31, 32, 11, 12), one of the elastic fasteners is disposed on the first slidable component, and the other elastic fastener is disposed on the second slidable component; two of the grooves (31, 32) are disposed on the needle base, and the other two grooves (11, 12) are circumferentially disposed on an exterior wall of the first slidable component; the elastic fasteners (13, 21) and the grooves (31, 32, 11, 12) are adapted for engaging with each other when the first slidable component and the second slidable component slide to completely shield the needle head or when the needle head is completely exposed, so as to limit the movement of the first slidable component and the second slidable component, one end of the second slidable component close to the hose has a smooth projection portion circumferentially disposed thereon.