Abstract: Mega projects pose complex governance challenges due to their extremely large scale, thus requiring the comprehensive intervention and prudent management from the state. The case study of the West-East Gas Transmission shows that the scale of the mega project leads to issues of information gap for decision-making and vague plans, as well as governance challenges such as project integration interaction and dilemma of multi subject collaboration. To cope with such burdens, 1) China shapes the depth and social legitimacy of mega engineering strategies with the will of the country, through strategic framing and engineering goal construction; 2) China bridges the gap between the ideal optimal solution and group decision-making results with collective rationality, through optimal decision-making and group intelligence support; 3) China integrates fragmented governance authority through leadership group coordination, high-level authority promotion, and political coordination, thus forming an effective intergovernmental governance synergy; 4) the state power, through a state-led organizational network, is deeply embedded in the field of engineering construction, thus achieving management coordination through the active operation of state capabilities. The national governance logic of mega projects can be summarized as comprehensive intervention, strategic coordination, prudent management, and effective governance. Its research helps to expand the national theory of mega engineering governance and deepen the understanding of China's mega engineering governance and decision-making process.

Key words: Mega projects, West-East Gas Transmission, national governance, stable control, strategic coordination