Abstract: In advanced avionics systems, the date communication system requires high speed and hybrid traffic. A scheme of distributed fiber-optic network system was presented based on the design consideration of distributed control, real-time access and fault-tolerance. Along with designing the architecture and choosing the protocol, the critical technology points of the scheme were analyzed emphatically, including fiber-optic links, media access control(MAC) protocol, fault- tolerance, topology technology and network management software. The analysis result indicates that the distributed fiber-optic network based on IEEE 1394b bus can provide deterministic and reliable communication in which the Gb/s fiber-optic link can meet the necessary of bit error rate (BER) with abundant link margin of 13dB. Therefore it has advantages of high bandwidth, low delay and flexible expandability.