The invention discloses an Ethernet communication method and system and an SDN exchanger. The method comprises the steps that the SDN exchanger reports the MAC address learned locally to an integrated controller, and the integrated controller issues forwarding tables of forwarding ports corresponding to target MAC addresses to all SDN exchangers under a management domain based on whole network topology automatic finding and route computing based on strategies; and the SDN exchangers achieve Ethernet frame forwarding according to the MAC address forwarding tables learned locally and the MAC address forwarding tables issued by the integrated controller. The integrated controller issues the MAC address forwarding tables to the SCN exchangers in the management domain, the boundedness that a traditional Ethernet exchanger learns whole network MAC addresses through a data forwarding plane is avoided, and the problems that broadcast storm and spanning tree protocols exist in the traditional Ethernet, so that a large amount of redundancy chain blocking is caused, network convergence speed is slow, and traffic engineering cannot be achieved are solved.