The invention provided an OpenFlow exchanger message security monitor and control method based on an OpenFlow protocol. The OpenFlow exchanger message security monitor and control method based on the OpenFlow protocol includes the following steps that an SDN (software defined network) controller exchanges with an OpenFlow exchanger through the OpenFlow protocol, and defines flow table items according to a rule; messages which pass through an industrial Ethernet exchanger are transmitted into the OpenFlow exchanger, and matched with the flow table items in a flow table of the OpenFlow exchanger; the industrial Ethernet exchanger sends the messages with source IP (identification of position) addresses changed to a convergence layer, and completes security control treatment of the messages from an access layer to the convergence layer. The OpenFlow exchanger message security monitor and control method based on the OpenFlow protocol uses a cleaning function of the OpenFlow exchanger based on a matching field appointed by the flow table in the OpenFlow protocol to throw away illegal messages sent to the industrial Ethernet exchanger and send legal messages to the OpenFlow exchanger twice, and thereby achieves centrally controlled message detection so as to guarantee security reliability of message transmission from the access layer to the convergence layer in an electric power system.