The invention discloses a software-defined network message forwarding method and system. The method comprises the following steps: a switch detects a correlated host of a port of the switch; when the host leaves the correlated port, the switch actively deletes table items correlated to the host in a local flow table; the switch reports flow table delete information to a network controller; and the network controller reprocesses a message to be forwarded according to the received flow table delete information. When the switch inspects that the correlated host on the port of the switch leaves, the switch actively deletes the table items correlated to the host in the local flow table and actively reports to the network controller so that the network controller can timely acquire the generated transferring of the position of the host, new processing measures are taken for subsequent messages to be forwarded and thus message loss caused by transferring of the position of the host can be effectively avoided.