A needle safety assembly device for a hollow needle comprising a frame or protective band (3.9) surrounding, at least in part, a needle safety element (2), wherein the frame or protective band (3.9) comprises a distal wall or bracket (3c), a first stay (3a) and second stay (3b), wherein the first stay and second stay (3a, 3b) are connected at the distal ends by the distal wall or bracket (3c), a needle safety element (2) slidably mounted on a needle shaft (1.1) having a needle tip (1.2), the needle safety element (2) comprising two movable arms (2.3, 2.4) which intersect each other, wherein at least one of the movable arms (2.3, 2.4) has a bent distal end wall abutting on the needle shaft in a ready position and covering the needle tip in a protective position； wherein on at least one of the first stay (3a) and second stay (3b), a lug (3.4a, 3.4b) is formed in the middle portion extending in the peripheral direction.
