The present invention discloses a method for controlling transmission security of an industrial communication flow based on an SDN architecture. The method comprises: designing a flow security control module in a management controller, performing in-depth parsing on industrial communication flow data, matching the parsing result with each preset industrial rule policy, and executing a control processing operation of the industrial rule policy, to implement transmission control of an industrial communication flow. The management controller comprises an industrial rule policy database used for storing all industrial rule policies set by a user. An SDN switch maintains a structure of a flow table, and an industrial communication flow is forwarded according to the flow table. The flow table comprises a security control identifier used for indicating whether security transmission of this communication flow needs to be controlled. The present invention can detect the legality of an industrial communication data flow, to control access of industrial communication that does not conform to an industrial rule policy, so that the security and reliability of industrial control systems based on an SDN architecture are guaranteed.