A blood sampling needle has a shell, a trigger seat, a needle stand, an elastic resetter and a safety switching member. The shell is provided with inner wall, retaining space, needle outlet and insertion end. A through-flange is formed into the shell. The through-flange and inner wall form a release groove with a tapered end-face. The trigger seat is mounted into the retaining space in a moveable state. The trigger seat has a control end and a rod. An axial chamber is opened on the rod so that two elastic release blades are formed on the rod, and also accommodated correspondingly into the release groove. An abutting bevel edge is formed at the bottom of the elastic release blade, and mated with the tapered end-face of the release groove in an oblique surface. The present invention saves structural members, reduces fabrication cost with better safety and applicability.