Permanent marking device for steel pipe

The utility model relates to a permanent marking device for a steel pipe, belonging to the marking device. The permanent marking device comprises an upper shaft, a lower shaft and a character die, wherein the upper shaft is provided with a feed pressing roller, the lower shaft is provided with a mill roller, the character die is connected with the encircle part of the mill roller in a detachable mode. The steel pipe can be permanently marked by utilizing the permanent marking device, and various marked parameters can be conveniently adjusted.