With the continuous development of avionics systems towards greater integration and modularization, traditional aircraft buses such as ARINC 429 and MIL-STD-1553B are increasingly facing challenges in meeting the demanding requirements of next-generation avionics systems. These traditional buses struggle to provide sufficient bandwidth efficiency, real-time performance, and scalability for modern avionics applications. In response to these limitations, AFDX (Avionics Full-Duplex Switched Ethernet), a deterministic network architecture based on the ARINC 664 standard, has emerged as a critical solution for enabling high-speed data communication in avionics systems. The AFDX architecture offers several advantages, including a dual-redundant network topology, a Virtual Link (VL) isolation mechanism, and well-defined bandwidth allocation strategies, all of which contribute to its robustness and reliability. However, with the increasing complexity of onboard networks and multi-tasking scenarios, the existing AFDX protocol still faces challenges in certain areas. Notably, there are issues related to latency jitter control under extreme network loads, efficiency in redundant link dynamic switching, and the assurance of timely and safe transmission of mixed criticality data. To address these challenges, this paper proposes an enhanced data transmission mechanism that builds upon an improved AFDX architecture. This mechanism introduces the construction of Virtual Links, creating a point-to-point network that provides deterministic Quality of Service (QoS) guarantees. Furthermore, a parallel redundant structure is incorporated to further enhance the reliability and fault tolerance of data transmission, ensuring that critical data is transmitted accurately and efficiently in complex, high-demand environments. This research aims to optimize the overall performance of AFDX systems, supporting the evolving needs of modern avionics networks.