The article discusses the development of structured satellite-UAV-terrestrial networks for 6G Internet of Things (IoT). Current 5G networks have limitations in coverage, especially in remote areas, prompting the need for a more comprehensive solution. The proposed approach integrates satellites, unmanned aerial vehicles (UAVs), and terrestrial networks to provide universal coverage for a massive number of IoT devices. This hybrid network faces challenges due to the heterogeneity and dynamics of space/air/ground links, leading to high system complexity. To address this, the authors propose creating and exploiting hierarchies in the integrated network, inspired by the synergies in the human body. Four basic structures are introduced: arm-hand, broadcast-communication, hand-foot, and eye-foot. These structures are designed to handle different aspects of coverage and communication in the integrated network. Additionally, a process-oriented on-demand coverage method is proposed, which characterizes the system behavior as a series of events over time, enabling efficient orchestration of heterogeneous basic structures. This method operates at a mesoscopic scale, between conventional micro and macro scales, to solve the complexity problem. The article also outlines open issues for promoting the agility and intelligence of structured satellite-UAV-terrestrial networks, including the need for new performance metrics, a new network framework, and addressing data exchange issues. The proposed method aims to provide a more efficient and intelligent network for 6G IoT, with a focus on systematic thinking and process-oriented optimization.The article discusses the development of structured satellite-UAV-terrestrial networks for 6G Internet of Things (IoT). Current 5G networks have limitations in coverage, especially in remote areas, prompting the need for a more comprehensive solution. The proposed approach integrates satellites, unmanned aerial vehicles (UAVs), and terrestrial networks to provide universal coverage for a massive number of IoT devices. This hybrid network faces challenges due to the heterogeneity and dynamics of space/air/ground links, leading to high system complexity. To address this, the authors propose creating and exploiting hierarchies in the integrated network, inspired by the synergies in the human body. Four basic structures are introduced: arm-hand, broadcast-communication, hand-foot, and eye-foot. These structures are designed to handle different aspects of coverage and communication in the integrated network. Additionally, a process-oriented on-demand coverage method is proposed, which characterizes the system behavior as a series of events over time, enabling efficient orchestration of heterogeneous basic structures. This method operates at a mesoscopic scale, between conventional micro and macro scales, to solve the complexity problem. The article also outlines open issues for promoting the agility and intelligence of structured satellite-UAV-terrestrial networks, including the need for new performance metrics, a new network framework, and addressing data exchange issues. The proposed method aims to provide a more efficient and intelligent network for 6G IoT, with a focus on systematic thinking and process-oriented optimization.