Grounded in the knowledge-based view and the emerging logic of digital knowledge governance, this study investigates how blockchain adoption strategies reshape inter-firm knowledge-sharing and sustainable innovation. A game theory and decision-optimization model is developed to capture the interplay among blockchain cost, knowledge trust, and collaboration incentives under four adoption scenarios between knowledge creators and users. The results uncover a double-threshold mechanism: when blockchain costs are high, the technology suppresses collaboration by increasing coordination frictions; yet as costs fall below a critical level, blockchain shifts from a trust-reinforcing tool to a catalyst for co-creation efficiency and joint environmental performance. Interestingly, partial adoption can yield a trust paradox-enhancing local reliability but diminish system-wide innovation synergy. As adoption diffuses, the equilibrium dynamically evolves from non-adoption to asymmetry and eventually bilateral digital trust, producing higher social welfare and resilience. Among asymmetric modes, creator-led adoption consistently outperforms user-led adoption, underscoring the strategic value of upstream knowledge transparency. The findings extend the knowledge-based view to the context of digital trust architecture and provide actionable insights for policymakers and firms seeking to build trust-based, knowledge-driven, and digitally sustainable innovation ecosystems.