International investment arbitration mechanism is the main mechanism for resolving disputes between investors and countries, and the arbitration clause of the international investment agreements is the key clause in the adjudication of ISDS arbitration.However, the early investment agreements signed by China with the countries along the Belt and Road mainly focus on the protection of the interests of the host country, which is not conducive to the legal relief of China’s foreign investors. The summarization and sorting out of the reform of international investment agreement by United Nations Conference on Trade and Development summarizes and sorts out the reform problems of international investment agreements has provided a reference for countries to accelerate the reform of the provisions of the modernization of the older generation of international investment agreements.The effective and implementation of Regional Comprehensive Economic Partnership Agreement in 2022 provides an opportunity for the reform of the international investment dispute settlement mechanism under the Belt and Road Initiative.The reform of the investor-state dispute settlement mechanism under the framework of China’s Belt and Road Initiative can be carried out on the basis of bilateral agreement, regional multilateral agreement by improving the entity clause of the source of bilateral, regional and multilateral agreements.