Based on the current challenges of intensified international investment risks and the lagging traditional relief mechanisms under the framework of the Belt and Road Initiative, this paper explores the effective path of reconstructing the international investment risk prevention and control mechanism by applying blockchain technology. The distributed ledger, smart contracts, and information security and transparency features of blockchain can help to reconstruct the international investment risk prevention and control mechanism: by building a trusted data platform to bridge the information gap and achieve precise risk early warning; by using smart contracts to automatically execute contract terms and reduce the risk of performance from the source; and by applying on-chain arbitration to solidify evidence and accommodate multi-jurisdictional rules, thereby enhancing the efficiency and fairness of relief. Drawing on successful domestic cases, under the premise of respecting national sovereignty, a multi-jurisdictional alliance arbitration chain can be established, with the deployment of full-cycle on-chain evidence preservation and automated risk control contracts, to construct a "sovereignty-technology" balanced legal supervision framework, providing a digital solution for international investment risk prevention and control under the framework of the Belt and Road Initiative.