System and method of dynamically selecting an egress edge node for data transmission between different autonomous systems based on real-time route performance detection. With respect to a destination node located in a second autonomous system, a plurality of edge nodes in the first autonomous system each operate to detect route performance in real-time and send the detected information to a control center for evaluation. The evaluation results are compared and used to select an optimal edge node and an associated link for transporting data between the source node and the destination node. To switch from a first edge node to a second one, the IP address of the source node contained in the data packets are converted from an address assigned to the first edge node to an address assigned to the second edge node.