To solve the constraint that the heavy-duty machineries had wide dispersion working region, treatment failure diagnosis of which was not convenient, the general remote diagnosis platform system of heavy-duty machinery for the electrical control systems was designed. With analysis of network communication protocol, and following the "open and close" system design principle, network communication part was designed to relatively independent subsystem for remote diagnosis function easy extending to new heavy-duty machinery. With a long time verification of field operation, the proposed network communication mechanism was proved satisfying the system function and performance requirement.