Abstract: As a critical tool used in the production process of the seamless steel tube,the performance of the piercing plug directly influences the productivity and the product quality. Systematically and comprehensively elaborated here in the article is the current situation of the research on the piercing plug for the seamless steel tube,and also analyzed are the mechanism of the failure as occurring under extreme operation conditions,and the causes for common failure types such as plug nose dent,surface steel sticking,axial cracking and oxide film peeling and etc.,and the inherent correlations between such failures and the processes parameters. Furthermore the characteristics,the performance,and the application scope of the alloy steel plug and the molybdenum alloy plug are discussed. Moreover the measures for improving piercing plug performance are systematically described, including the structural design and the surface strengthening technologies,etc. Finally the plug research direction is discussed.