Abstract:From the perspective of policy change, this paper builds the "structure-population-environment" evolution analysis framework of the innovation ecosystem of new energy vehicles, and the development of China's new energy vehicle industry can be divided into four stages: technology exploration, demonstration and promotion, rapid development and quality development. Based on the patent joint application data of China's new energy vehicle industry from 1991 to 2021, Establish a patent cooperation network for industrial technological innovation. The research results show that China's new energy vehicle industry policy change and innovation ecosystem evolution is a process of co-evolution, the State Grid Corporation of China company gradually become the core node in network, research institutions and universities gradually become secondary core nodes. The breadth of subject symbiosis increases but the depth decreases, centricity and niche fluctuate less, the technological variability is always strong. And then put forward suggestions to promote the development of new energy vehicle industry: adhere to market leading and government guidance and follow industrial laws; encourage breakthroughs in core technologies and build a technological innovation network with the deep participation of multiple parties; promote market competition and merger and reorganization; lay out a system of independent intellectual property rights to facilitate international technological competition.