Disclosed are a load sharing method and a device thereof, for dynamically realizing load sharing of user flows. The method of the embodiments of the present invention comprises: in the present invention, by deploying a data flow control plane, when a terminal is online, performing service layout by means of the data flow control plane, issuing a forwarding rule to a router so as to instruct the router to send a data message of the terminal to a target data plane, and at the same time, determining communication configuration information about a predefined service of the terminal and sending same to the target data plane. After a subsequent data message reaches the router, the router executes a policy route to forward the data message to a corresponding target data plane for service processing, such that policy routes generated by different terminals are different, and data planes forwarded to by the router are also different, thereby realizing load sharing. At the same time, the same type of data messages of different users can be forwarded to different application server instances, so that load sharing can be realized between the application server instances.