Abstract: The theory of disruptive innovation in national mega-projects is still lack of systematic understanding. This article will take China's high-speed railway project as an example to analyze the disruptive innovation pattern of national mega-projects. First of all, this paper systematically traces back to the theory of disruptive innovation and summarizes the connotations of disruptive innovations. Simultaneously, from the historical development of several typical national mega-projects in China, this paper summarizes the connotations of national mega-projects. Based on the two connotations, we summarize the theoretical basis of disruptive innovation in national mega-projects. Secondly, by analyzing the historical process of the development of China’s high-speed rail from the perspectives of technological innovation level-time dimension, market scale-time dimension and industry division dimension, we analyze the mechanism of the development of high-speed rail; by analyzing the mechanism of the implementation subject, the dominant factor and the key breakthroughs, we built the "Triple Three" pattern of disruptive innovation of China’s high-speed rail and analyze it from the perspectives of the innovation characteristics, scope of applications and innovation environments of disruptive innovation in national mega-projects. Finally, the conclusion is drawn and the research enlightenment of this article is analyzed from the perspectives of scope of applications of disruptive innovation in national mega-projects.