The rapid development of intelligent aviation technologies has increased the demand for high-reliability, real-time communication in airborne networks. Time-Sensitive Networking (TSN), with its high bandwidth, deterministic transmission, and low latency, has become a core solution. However, Unmanned Aerial Vehicles (UAVs), constrained by energy and bandwidth limitations, face challenges with traditional single-path routing, which is vulnerable to failures and data loss. Thus, redundant routing mechanisms are crucial for ensuring reliable service transmission. A major challenge is the inefficiency of current TSN technologies in handling burst traffic. Traffic surges can preempt critical services’ time slots, causing queuing delays and scheduling timeouts, which degrade communication performance. Therefore, research on redundant routing and traffic control for UAV-based TSNs is essential to enhance emergency communication and QoS. This study addresses service transmission reliability in UAV TSNs by proposing a multi-objective optimization-based backup routing mechanism. This approach mitigates the risks of single-path routing by optimizing end-to-end delay and energy consumption, while selecting primary paths that meet QoS requirements. Additionally, spatial redundancy is introduced, where primary path nodes monitor network conditions and dynamically compute backup paths. In case of failure, the system seamlessly switches to a backup path, ensuring service continuity. Simulations show that this strategy improves energy efficiency by 39.1%, arrival rate by 17.6%, and reduces average end-to-end delay by 26%, demonstrating its effectiveness.