As an epoch-making weapon in the filed of new domain forces with new combat capabilities, electromagnetic rail gun can bring revolutionary changes to the future battlefield for its ultra-high firing rate, ultra long range, and super strong striking power. However, due to the electromagnetic emission is a complex and harsh multi field coupling environment that integrates electricity, magnetism, heat, and force, the gun barrel life remains the key issue that restricts the engineering of rail gun. This article provides an overview of the main factors that affect the lifespan of electromagnetic rail gun barrel, and deeply analyzes the mechanism of the problem. Finally, the main technical measures currently available for extending the lifespan of electromagnetic rail gun barrel are elaborated from three aspects: upgrading material performance, improving processing and assembly accuracy, and optimizing structural design. This article can be used as reference and inspiration for accelerating the great-leap forward development of electromagnetic rail gun.