Abstract: The overview of FAO (fully automatic operation) system construction is expounded, and the idea of digital management of FAO system core electromechanical engineering based on the ′digital and mechanical convergence′ is proposed. By using analytic hierarchy process (AHP), centering the goal of ′implementation based on grades′ for FAO system electromechanical, and by analyzing the management objectives, activities and business processes of the core electromechanical system construction layer by layer, the hierarchical digital structure of the core electromechanical system management is formed, and the injection and governance of system digitalization and management digitalization is carried out, so as to promote the high-level delivery and sustainable operation and maintenance of FAO system.