An automotive steering rack stroke adjusting device is disclosed that detects a change in a gap defined between steerable wheels and a vehicle body depending on a change in the stroke of the steerable wheels using a vehicle height sensor, and automatically adjusts the rotation of a plurality of rotary bodies with respect to a stop plate of a steering rack, so that the optimized maximum stroke of the steering rack can be set according to the driving conditions of the vehicle. Furthermore, the present invention is able to increase an adjustment range of the stroke of the steering rack, so that a minimum rotation radius of the vehicle may be reduced, thus markedly enhancing the driving convenience.