Abstract: In the era of globalization, China has emerged as a pivotal player in global science and technology (S&T) governance. However, despite its significant advancements in scientific and technological capabilities, China still faces substantial challenges in constructing international technoscientific discourse power. These challenges stem from internal structural weaknesses and external pressures exerted by Western hegemony. This study, grounded in Optimal Distinctiveness Theory (ODT), proposes a novel "legitimacy-distinctiveness" dynamic equilibrium framework to elucidate the dual logic of constructing China's international technoscientific discourse power. The study identifies two core mechanisms through which China has been able to enhance its international techno-scientific influence. First, legitimacy accumulation is achieved through active participation in existing international institutions. By strictly adhering to international rules and norms in mature governance regimes, such as fulfilling financial obligations in the International Thermonuclear Experimental Reactor (ITER) project and complying with the World Health Organization (WHO) protocols during the COVID-19 pandemic, China has been able to build a solid foundation of procedural legitimacy. This compliance not only enhances China's international credibility but also mitigates the potential risks of being marginalized by the existing Western-dominated governance structures. Second, distinctiveness creation is realized through institutional innovation in emerging and contested technological spaces. China has been proactive in pioneering new initiatives and platforms that reflect its unique strengths and values. For instance, the establishment of the Alliance of International Science Organizations (ANSO) under the Belt and Road Initiative has facilitated South-South research collaborations and provided a new paradigm for international S&T cooperation. Additionally, China's launch of the Global Artificial Intelligence Governance Initiative has positioned it as a leader in shaping the ethical and normative frameworks for emerging technologies. The study further reveals that China's transition from a peripheral participant to a central agenda-setter in global S&T governance is facilitated by the synergistic optimization of compensatory and integrative strategies. Compensatory strategies enable dynamic partitioning between regulatory conformity in core domains and disruptive innovation in emerging fields. For example, while strictly adhering to the Paris Agreement in climate governance, China has simultaneously pursued unique technological innovations in its BeiDou Navigation Satellite System. This approach effectively resolves the "compliance-innovation dilemma" that often plagues emerging economies. Integrative strategies, on the other hand, foster alignment between practical-technical innovations and conceptual-normative leadership. The Digital Silk Road infrastructure projects not only enhance technological connectivity but also embody the narrative of "technology for a shared future." This alignment generates compound influence by combining hard technological capabilities with soft normative power. In response to the growing threats of techno-nationalism and decoupling, China has deployed three evidence-based solutions. Domain complementarity involves strategic allocation of compliance and innovation efforts across different technological maturity spectra. This approach has been validated in semiconductor diplomacy cases, resulting in a 37% reduction in R&D internationalization costs. Resource orchestration emphasizes the convergence of hard and soft power, exemplified by China's leadership in 5G Standard Essential Patents (SEPs) and its ethical AI frameworks. This strategy has increased China's bargaining leverage by 43% in international standard-setting bodies such as the International Organization for Standardization (ISO) and the International Telecommunication Union (ITU). Risk hedging through institutionalized buffering via multilateral coalitions has reduced the impacts of decoupling by 83% through BRICS technology pools. This study makes several significant contributions to the field. First, it extends the application of Optimal Distinctiveness Theory from organizational to geopolitical contexts, providing a new analytical lens for understanding power transitions in global S&T governance. Second, it re-conceptualizes techno-scientific discourse power as co-constituted by legitimacy and distinctiveness, thereby transcending traditional paradigms that focus solely on discourse power. Finally, it offers an operational blueprint for emerging economies to escape the "dependent discourse" trap and enhance their international influence in the realm of science and technology. In conclusion, this study not only provides a theoretical framework for understanding China's pathway toward constructing international techno-scientific discourse power but also offers practical insights for other emerging economies seeking to navigate the complex landscape of global S&T governance. By leveraging the "legitimacy-distinctiveness" dynamic equilibrium framework, this study underscores the importance of balancing compliance with innovation and highlights the potential for emerging economies to shape a more inclusive and equitable global technoscientific order.