With the development of the low-altitude economy, a massive number of unmanned aerial vehicles (UAVs) are being deployed in logistics, cruising, communication, and other scenarios, leading to a rapid increase in collision risks. To enhance safety, a structured management method for UAVs in low-altitude airspace is proposed. This method utilizes an intent-driven digital twin system that organizes low-altitude airspace into layers and facilitates the planning of UAV cruising paths. This study simulates the energy consumption and collision risk of logistic, cruising, and communication UAVs in layered airspace under four types of cruising routes, with the collision risk in unstructured airspace simulated as a control group. The approach aims to reduce collision conflicts among UAVs and between UAVs and terrestrial structures, while simultaneously improving UAV performance and energy efficiency. The cruising patterns include various strategies such as random cruising, circular cruising, hovering, vertical boundary cruising, and coordinated cruising with a single UAV. Ultimately, the management of UAV layers and cruising strategies for multiple intent-driven UAVs are integrated and coordinated within the digital twin system, effectively reducing UAV collision risks and energy consumption.