Internet of Things (IoT) as a new emerging and fast growing technology has attracted lots of attention from worldwide recently. Successful applications of IoT have been demonstrated in many fields. However, IoT is still at its infant stage when it comes to the applications in product life-cycle energy management (PLEM). In this paper, the concept, characteristics, and applications of IoT are briefly introduced first. Then, the energy consumption involved in the three phases of product life cycle (i.e., design, production, service) are concluded and analyzed. But what is the relationship between product lifecycle energy consumption and the IoT technology? Whether the IoT concept and techniques can be employed in manufacturing to reduce the energy consumption during design, production, serve process, and what are the potential applications? Therefore, in order to answer these questions, the existing applications of IoT in PLEM are summarized, and the potential applications and challenges of IoT techniques in PLEM are analyzed and pointed out.