Abstract:    The tension between the international situation and domestic development has made the problem of "Stranglehold" of key technologies an important challenge restricting the sustainable development of my China′s economy and society. Hence, exploring innovative development paths to respond to and solve this challenge has become an important topic in the field of knowledge innovation. Fundamentally, knowledge innovation is the source and foundation of key core technological innovations and breakthroughs. It not only inspires and guides the research and breakthroughs at the source of basic research of key technology, but also acts on each innovation stage from experimentation, development to marketization, providing it with a direct or indirect knowledge base and ideological source. It should be recognized that the so-called " Stranglehold " of key technologies does not only refer to the "stuck" of a single technology, but a non-self-controllable problem of a knowledge cluster formed by a "package" of technologies in the industrial chain of a certain field. From this point of view, the "Stranglehold" challenges of key technologies are a systematic problem. According to the idea of "systematic solution to systemic problems", the overcoming and breakthrough of key technologies is a complex systematic project, which requires the overall design and planning of systematic thinking. 
   Faced with the challenge of "Stranglehold" of key technologies, it is urgent to systematically improve the overall performance of basic research in China. However, the existing knowledge innovation research in China is still based on the "triple-helix" (university-enterprise-government) framework, which cannot reflect the parallel coexistence and co-evolution characteristics of diversified subjects, diversified paths and diversified knowledge innovation modes in the new era. Thus, it fails to find an integrated view or an appropriate framework when researchers look into the "Stranglehold" challenge. To explore the problem of "Stranglehold " from a systematic perspective, it is necessary to establish a theoretical framework of knowledge innovation system that is suitable for the development characteristics of the new era. And use this as a tool to examine the core challenges of China′s current knowledge innovation policies and practice.
   The research focuses on the following topics: Firstly, from the perspective of the evolution of the knowledge innovation paradigm, what are the core challenges of the "Stranglehold " problem of key technologies? Secondly, what are the core features of the "Knowledge Innovation Ecosystem" in the new era, and how to construct a theoretical tool that reflects this multi-agent and cross-layer interaction to describe and analyze the process and mechanism of knowledge innovation? Thirdly, based on the "multi-spiral" ecosystem framework of knowledge innovation in the new era, what are the possible paths to solve the systemic challenges of key technologies? Based on the investigation of the characteristics of the transformation of knowledge innovation paradigm, this study explores the knowledge innovation ecosystem of "N-tuple helices" and to form an embedded dynamic network with fractal characteristics. Besides, this study discusses the feasible path and specific measures to systematically improve China′s scientific research innovation ability in face of the "strangel hold" challenge.

Key words: technology "stranglehold";knowledge innovation, key technology breakthrough, innovation ecosystem, multiple helices