Abstract: In order to satisfy the requirement of high throughput and high reliability of data transfer in airborne dis-tributed computation system,this paper introduces fault——tolerance technologies based on fiber channel arbitrate loop (FC——AL) including hardware redundancy and reconstruction arithmetic.The emphases of discussion are de-sign of Fiber Channel interface circuit,interconnection structure of four——redundancy FC——AL.Also this paper dis-cusses fault classifications,mode switch and reconstruction arithmetic about FC——AL.