Abstract: To promote the deepening reform of the occupational safety and health (OSH) legal system of national defense industry in China, a systematic study on the United States (US) defense industry OSH legal system was conducted from three aspects:history, macro design, and micro construction considerations. In terms of macro design, the US defense industry emphasizes on the decentralization and balance of the supervision power among different OSH supervisory agencies to prevent abuses of power. In terms of micro construction, the US pay more attention to the systematization, update mechanisms, supervision approaches, and the definition of supervision responsibilities in constructing the OSH legal system of national defense industry. The US experience revealed four enlightenments for China:clarifying supervision responsibility, improving national legal system, refining regulatory developing and amending mechanisms, and encouraging diversified supervision approaches.