The invention provides a method for protecting and restoring a service comprising inevitable nodes. An ant agent generated through an ant colony algorithm regularly is used for collecting the node state information from a source node to a destination node in a network, and therefore a node state transition probability table is updated. The method comprises the specific steps that first, an inevitable node sequence is established; second, segmented routes between the source node and the inevitable nodes and between the destination node and the inevitable node are acquired, and the segmented routes are integrated; third, breakdown nodes are detected; fourth, restored routes are obtained. Compared with the prior art, the method for protecting and restoring the service comprising the inevitable nodes can shorten restoring time and quickly obtain the restored routes when the service needs to meet the specific condition that certain inevitable nodes are passed through, and therefore the success rate of service restoring is improved.