The invention discloses a line bus integrated backup protection method using a pilot comparison principle based on the fault direction. The method comprises the steps: taking a breaker as the center, determining the electrical elements related with the breaker and the backup protection functions, and incorporating the backup protection functions in the same protector to complete; determining the fault direction information is interacted among which protectors, and the mode for interaction of the fault direction information; comparing the fault direction information when a fault occurs, and determining the position wherein the fault is according to the compared result of the fault direction information; and determining the motion strategy for backup protection. The line bus integrated backup protection method using a pilot comparison principle based on the fault direction has the advantages of reducing the quantity of backup protection, simplifying the coordination relationship among backup protection, simplifying the control loop of the breaker, improving the reliability for working of a secondary system, being able to determining the fault position rapidly and reliably when the fault occurs, and improving the rapidity and the reliability of the backup protection motion.