Mega-events marketing is currently one of the effective measures for urban development. It also has an important enlightening significance to the marketing promotion and strategic development of libraries. This article mainly elaborates on the concepts of mega-events and mega-events marketing. Based on the aspects of nature, content and impact, this study analyzes four different mega-events, including the International Advocacy Program promoted by IFLA, "Austria Reads. Meeting-point Library" Campaign launched by Austrian Library Association, Shanghai Library's contribution to Shanghai World Expo and the event that South Korea's Incheon was elected as the World Book Capital. We summarize the key steps of the library’s use of "mega-events" as follows: clarifying the development goals of the mega-events, forming a dedicated team directed at the mega-events, constructing the marketing elements of the mega-events, and establishing the evaluation mechanism. The key points of the marketing strategy for "mega-events" include gaining support from the government and library leaders, promoting the professionalism of the library team, clarifying and continuously improving the strength of the library and building a good social partnership.