The utility model relates to a fixing device for disc brakes. The connected position of a fork frame of a vehicle body and the disc brake is provided with a group of or more than a group of fixing devices. The device is composed of a ball body, a pressing block, a forcing element, a shaft lever, a washer and nuts. Through relaxing the forcing element, the pressing block can not tightly buckle the ball body to cause the ball body to be attached to the shaft lever to produce axial displacement, or ball rotation principle is used for producing universal offset performance. The disc brake can produce regulation action without limitation of displacement following the ball body to further achieve the purposes of convenient correction and positional adjustment, zero error and reinforced operational safety of the brake.