Steering apparatus

The present invention relates to a steerage gear having a steering column (3) with a steering pinion wheel (4) and a steering rod (7) with a meshing engagement system (6). The steering pinion wheel (4) is engaged with the meshing engagement system (6), the steering rod (7) is in an installation that it can rotate in circumferential vision and move in longitudinal vision, a steering device (2) hasa variable-gear-ratio, the meshing engagement system (6) of the steering rod (7) is preferentially set into a gear module (14) capable of rotating in circumferential vision from the steering rod (7),therefore, a changeable transmitting ratio that is changing in circumferential vision from the gear module (14) between the meshing engagement system (6) and the steering pinion wheel (4) engaged with the meshing engagement system (6), each screw thread (18) of the gear module (14) is a stepless variation structure in circumferential vision.