A surgical operating instrument and a bending device thereof in the technical field of medical instrument are disclosed. A driving assembly of the bending device includes: a driving screw (9) which can be around its axis and rotatablely installed on a fixed handle (1), the axis of the driving screw (9) being parallel to the axis of an elongate body (6), and the driving screw (9) is provided with two sections of threads (901, 902), one section being left-hand thread (901), and the other section being right-hand thread (902) one driving rod (101) is meshed with the one section of threads (901), the other driving rod (102) is meshed with the other section of threads (902), and the distal sides of the two driving rods (101, 102) are connected with an end actuator (8) a rotary sleeve (4) concentrically sleeved outside of the driving screw(9), the rotary sleeve (4) and the driving screw (9) are in transmission connection through a gear assembly when the rotary sleeve (4) is positioned at its bending adjusting position. The stability of gear assembly matching between the rotary sleeve and the driving screw and the stability of the screw-thread fit between the driving screw and the two driving rods are high. The bending angle of the end actuator with respect to the elongate body can be controlled with high operation accuracy by means of the controlling of the rotation angle of the rotary sleeve.La présente invention concerne un instrument opératoire chirurgical et un dispositif de flexion de celui-ci dans le domaine technique des instruments médicaux. Un ensemble dentraînement du dispositif de flexion comprend : une vis dentraînement (9) qui peut être autour de son axe et installé de façon rotative sur un manche fixe (1), laxe de la vis dentraînement (9) étant parallèle à laxe dun corps allongé (6), et la vis dentraînement (9) est pourvue de deux sections de filetage (901, 902), une section étant un filetage gauche (901), et lautre section étant un filetage droit (902) une
