Disclosed is a blood-taking needle with automatic needle retraction, the blood-taking needle comprising: a needle seat (1) having a first cylindrical portion (11), a second cylindrical portion (12) and a tail seat portion (13)； a needle tubing (2) mounted within the first cylindrical portion (11)； a built-in sliding sleeve (3), wherein same is a long block with an approximately C-shaped cross-section and two open ends thereof, the second cylindrical portion (12) being mounted inside the built-in sliding sleeve (3) and being capable of sliding back and forth； a protective housing (4), wherein same is an elongated hollow housing with two open ends, the built-in sliding sleeve (3) being mounted inside the protective housing (4) and being capable of sliding back and forth； and a spring (not shown) sleeved on the first cylindrical portion (11). The tail seat portion (13) and the tail end of the protective housing (4) form a locking structure. When the tail seat portion (13) and the protective housing (4) are unlocked, the action force of the spring forces the second cylindrical portion (12) to slide backwards. When the second cylindrical portion (12) and the built-in sliding sleeve (3) are locked, the built-in sliding sleeve (3) continues to be driven to slide backwards and is locked with the protective housing (4), and at this point, the needle tubing is fully retracted into the protective housing (4). The invention can prevent needle stick injuries and cross infection, and can reduce the damage to the inner walls of a patient's blood vessels due to the needle tubing, and the product design thereof is miniaturized.
