Method and system for establishing data transmission links

The application discloses a method and a system for establishing data transmission links. The method comprises: receiving a link establishment request including the path identifier and the link type sent by a source node, judging whether resource status of the current mode meets the requirements of QoS level of a data stream corresponding to the link type, if yes, establishing the link between the current node and the previous node, and judging whether the current mode is the last node of the link, if yes, sending response information to the source node hop-by-hop through the link, otherwise sending the link establishment request to the next node of the current mode to allow the next node to repeat the step of judging whether the resource status of the current mode meets the requirements of QoS level of a data stream corresponding to the link type and subsequent steps. According to the method and the system for establishing the data transmission link, transmission links can be established for the data streams having the same QoS level, multi-level transmission of the data is ensured and QoS requirements of the data is met.