The utility model relates to a quick adjustment device, and especially relates to a rotary combined type quick-replacing printing block capable of quickly adjusting and replacing the lettering content needed by optical cables. According to the technical scheme, the rotary combined type quick-replacing printing block comprises a shell and a rotating shaft penetrating through the shell, wherein a model rotating disc, three groups of number rotating discs and a standard rotating disc all capable of rotating around the rotating shaft are sequentially arranged on the rotating shaft and are all provided with convex characters. By adoption of the technical scheme, the rotary combined type quick-replacing printing block has the positive effect of quickly adjusting the number of cores and the models and types of the optical cables (tubes) according to the required contents of products. In use, the printing block only needs to be mounted and adjust in height once, and the contents of the optical cables (tubes) can be adjusted subsequently without stopping under the parallel condition. For the rotary combined character block based on technical scheme, models can be replaced quickly, the number of cores can be replaced quickly and the standards also can be replaced quickly, and the adjustment is quick, so that the efficiency of productivity is high, labor is saved, time is save, material is saved, and the printing block can be convenient to maintain and easy to manage.