Abstract: A real-time communication mechanism for industrial Ethernet is introduced.A real-time communication entity is added to the tansport layer and data link layer,and it can avoid communication collisions by scheduling information transmission under the condition of not modifying the Ethernet communication mechanism.The real-time communication schedule must coordinate with the function block schedule in industrial Ethernet.The schedule mechanism of the function block is analyzed,and the constructing strategies of periodic time schedule list and non-periodic communication schedule list are proposed by combining the function block schedule and the real-time communication schedule.