Aiming at the development status and existing problems of sensor access technologies for wireless Internet of Things (IoT), to avoid similar situations in the application of Internet of Things in energy (IoTE), the present sensor access technology should be optimized and improved. At first, this paper introduces the network characteristics and structure of IoTE, which can be flexibly selected according to different application scenarios for the IoT field network. Then, according to the low power consumption requirements of IoT sensors, an efficient wake-up mechanism suitable for IoTE networks is proposed. By applying the mechanism, the low power nodes can quickly identify the invalid wake-up frames and return to sleep quickly. Finally, theoretical analysis and calculation of power consumption are carried out for the wireless IoT network. Compared with the traditional wake-up mechanism, the proposed passive wake-up mechanism has obvious advantages in low power consumption and low latency.