Since the Belt and Road Initiative (BRI) was proposed, the pace of projects investment and construction has been accelerated, which accumulated much experience in the going-out strategy in the context of BRI. Modern railway projects are characterized by "natural monopoly", as well as huge investment and extensive geographical coverage. Moreover, their construction is a typical transformative project, which embedded the necessary institution and culture. The countries along the Silk Road are characterized by weak institutional construction, lack of regulatory system, and underdeveloped industrial civilization, therefore they cannot operate and manage the railway system. In this context, all links, including financing, design, construction, and operation, should be considered in the going-out process of China's railway system. The transfer subject is the technology-institution-culture nexus which takes railway technology as the core. In other words, to achieve railway technology transfer successfully, the host countries should offer rational institutional guarantee and cultural adaptation. Besides, the technical standard of railway construction, management mode, and industry chain in the process of railway operation and maintenance need to be localized. Mombasa-Nairobi standard gauge railway is a successful going-out case of China's railway technology. Learning from the case, this paper proposed the concept of "embedded technology transfer" and constructed the theoretical model of technology-institution-culture nexus transfer. The results can provide references for the transfer of transformative projects or technologies between countries with different institutions and cultures.