Abstract: Seamless steel pipe piercing plug is prone to early failure due to harsh service conditions (high temperature, complex forces, etc.), which seriously affects its service life and dimensional accuracy. The preparation of protective coating on the surface of piercing plug is effective to solve this problem. At present, the main protective coatings applying to the piercing plug are alloy coatings, ceramic coatings, and ceramic particle-reinforced metal-based composite coatings, among which the ceramic particle-reinforced metal-based composite coatings have excellent overall performance and figure out the key development direction of piercing plug protective coatings. In order to further improve the coating protection effect, the protection performance can be optimized by using the active element effect and conducting gradient coating design and other approaches. This paper can provide reference for the development of long-life and highly reliable seamless steel pipe piercing plug.