Terminal operating systems for China's power Internet of Things (IoT) are highly fragmented and heavily dependent on the Linux kernel, which gives rise to kernel-level supply chain security risks. Additionally, they face issues such as long protocol conversion time, data silos, and high operation and maintenance (O&M) costs, making it difficult to meet the requirements of global interconnection and real-time response for source-grid-load-storage integration. Based on OpenHarmony, this paper constructs a componentized IoT system base for the power edge side, focusing on breaking through three key technologies: first, a power data acquisition subsystem supporting dynamic loading of multiple protocols such as Modbus/DLT645; second, a near-field O&M optimization method integrating QR code recognition, wireless communication, and big data; third, a parallel encryption and decryption technology based on software-defined hardware (combined with SM2/SM1/SM4/SM7 algorithms). In the application of the Sichuan virtual power plant project, the system achieves second-level equipment data acquisition and conversion, shortens the access time of new equipment by more than 85%, and increases the secure processing throughput by over 10 times. It effectively solves the coordination bottleneck of “source-grid-load-storage” and provides technical support for the new-type power system.