Service data flow transmission method and system

The invention provides a service data flow transmission method and system. The method includes the steps that a base station determines whether service data flow transmission needs to be carried out with a terminal through a wireless local area network access point during service data flow transmission between the base station and the terminal or not; if yes, the base station splits the service data flow so as to transmit the service data flow. By means of the technical scheme, wireless local area network polymerization at an access layer can be realized, the wireless local area network access point is effectively utilized for sharing flow, then the quality change of a wireless link is responded more flexibly, and a high service quality is realized for flow of the wireless local area network through a cellular network channel.