Abstract: The author provides an investigation of the currently used die-forged piercing plug made of 3Cr2W8V Steel and an introduction about the cast externally/internally water-cooled piercing plug involving such main aspects as material, structure and manufacture process flow.Compared with the die-forging process, the casting process is more cost effective.And so far as the said cast plug is concerned, relevant operational practice has proven that this kind of plug is in possession of advantages namely, lower cost, longer service life and being easy to make.It is worth spreading.