A lumbosacral anterior approach steel plate fixing device comprises a steel plate (2) and screws (2). Screw holes (4) are formed in the steel plate (1), and screw heads (6) of the screws (2) can be contained in the screw holes (4). The lumbosacral anterior approach steel plate fixing device further comprises locking nuts (3), the locking nut holes (12) which are adjacent to the screw holes (4) are arranged in the steel plate (1), and the locking nuts (3) can be maintained in the locking nut holes (12) in a rotatable mode. Concave surface parts (7) and convex surface parts (8) are arranged along the periphery of the locking nuts (3). In first locking nut rotating positions in which the concave surface parts (7) of the locking nuts (3) face the screw holes (4), the locking nuts (3) do not block the screw holes (4) while in second locking nut rotating positions in which the convex surface parts (8) of the locking nuts (3) face the screw holes (4), and the convex surface parts (8) can press the screw heads (6) of the screws (2) located in the screw holes (4). The present invention can simplify operation steps, lower the operation operating difficulty, and enable the complete set of the device to be compact in structure.Linvention concerne un dispositif de fixation de plaque dacier dabord antérieur lombo-sacré qui comprend une plaque dacier (2) et des vis (2). Des trous de vis (4) sont formés dans la plaque dacier (1), et les têtes de vis (6) des vis peuvent être contenues dans les trous de vis (4). Le dispositif de fixation de plaque dacier dabord antérieur lombo-sacré comprend en outre des contre-écrous (3), les trous de contre-écrous (12) qui sont adjacents aux trous de vis (4) sont disposés dans la plaque dacier (1) et les contre-écrous (3) peuvent être maintenus dans les trous de contre-écrous (12) en mode rotatif. Des parties de surface concave (7) et des parties de surface convexe (8) sont agencées le long de la périphérie des contre-écrous (3). Dans les premières
