Abstract:     Megaproject innovation has become an effective model of independent innovation in Chinese industry. This paper adopts the case study method, based on the general analysis framework of innovation ecosystem theory, and takes Shenhua Coal-To-Oil Indirect Liquefaction Demonstration Project of Four Million Tons Per Year as the case, to investigate the process of user enterprises leading the relevant parties under the common vision to participate in and cooperate in the realization of megaproject innovation in the way of innovation ecosystem. 
    The conclusion of this paper is that in the user-driven megaproject innovation ecosystem, the experience accumulation and participation ability of users enable them to promote the value creation activities as the orchestrator, collaborator and complementor. In the definition stage, as an ecological organizer, Shenhua defines requirements from the common vision of independent localization of major equipment and materials of coal-to-oil key technologies, so as to clarify the value creation content of each participant in the ecosystem. In this stage, the national leading mechanism is mainly in the design stage. As the ecological leader, Shenhua demonstrates the technology through pre-research and feasibility report. First, in the user-led innovation ecosystem of major projects, market approved conditional procurement and bidding, joint activities and coordination institutions established based on common interests are indispensable operating mechanisms. Second, user enterprises in megaprojects have dual identities: it not only bears the national strategic mission, but also represents the market foresight demand. Third, the experience accumulation and participation ability of users enable them to promote the value creation activities as the arranger leader, collaborator and complementor.
    In this stage, the market mechanism is mainly in the construction stage. As an ecological synergist, Shenhua integrates the advantages of the participants in the ecosystem to realize the project-oriented resource integration. This stage is mainly the ecological mechanism. In the commissioning stage, as an ecological complementor, Shenhua solves the challenges in the commissioning process through the technological innovation activities of complementary suppliers and complementors. In this stage, the ecological mechanism mainly needs to be explained. Due to the large scale and complex process of the project and the difficulty of collaboration, the mechanisms used in the life cycle of the project are often overlapping and repeated. In general, different phases of the construction mechanism have different focus.
     In terms of theoretical contributions, this paper puts forward the theoretical framework of user-driven innovation ecosystem, and analyzes the case of megaprojects. Based on this theoretical framework, two findings are drawn: First, in the innovation of complex product systems such as megaprojects, the unique application scenarios and process requirements of end users are conducive to the demonstration of megaproject design, organize and implement, and accelerate the innovation process of system participants, especially supplier groups. This is reflected in the ability of leading users to be the first to obtain market access qualifications and lead core technology suppliers with their accumulated experience and capabilities in open innovation cooperation. The joint actions of complementary technology providers based on a common vision not only increase the possibility of users adopting domestic technologies and products, but also provide market opportunities for domestic suppliers to develop and apply new products. It is a value creation activity based on symbiotic relationship, and then drives the co-evolution of relevant participants in the domestic industrial innovation chain with systematic value creation. Second, in the innovation ecosystem of megaprojects, end users bear dual missions. In megaprojects, end user enterprises are often central or state-owned enterprises, which shoulder both the public mission of the government and the market interests of enterprise users. End-user enterprises play the role of system integrator, and the government has a strong guiding role in ecological formation and joint cooperation. Its measures to promote scientific and financial support in the localization of market access conditions directly affect whether end-user enterprises can form an ecosystem around megaprojects and create value. 
     This paper has promoting significance for the practice and theoretical research of the organization of megaproject innovation. As a megaproject bearing public mission, it has increasingly become an important way to make breakthroughs in industrial technology. How can megaproject technologies and products built by users spread quickly and achieve market benefits? In the early stage, demand incentive measures such as government procurement targeted subsidies given by the government will help the diffusion and application of industrial technology.

Key words: megaproject, user innovation, innovation ecosystem, synergistic innovation