The IoT is one of the most significant recent innovations in information technologies, which has attracted extensive attention from both industry and academia due to its potential impact on various networking-related fields. The rapid development in IoT technologies has resulted in widespread application of this emerging networking paradigm in various disciplines. On the other hand, IoT faces some challenges that must be fully dealt with, among which scalability and energy efficiency are two critical issues. Topology control offers a promising approach to designing a large-scale and energy-efficient IoT. In this article, we first present a taxonomy of currently available topology control algorithms, and then propose a systematic approach to topology construction in IoT to achieve scalability and energy efficiency. We intend to provide researchers and practitioners with a big picture of the current research status in this area, and hope that this article may motivate more researchers to participate in largescale IoT design, development, and deployment.