Abstract: The international investment system is in crisis, and a growing number of countries are questioning whether the investor protection system provided by bilateral investment agreements is indeed beneficial to increase the flow of investment.Many countries around the world are carrying out drastic reforms in foreign investment laws.Taking South Africa's practice as a realistic starting point,with summarizing the reasons for the reform of South Africa's investment protection system and deeply analyzing the legislative intent of "Protection of Investment Law", this paper expounds its choice of safeguarding the regulatory power of domestic public interests through domestic legislation so as to provide recessive legal risk report and to reveal the significance of law reform for Chinese investors in South Africa during the process of "One Belt One Road".As for the authorities of South Africa,the challenge to establish a new investment protection system in the future lies in how to maintain a balance between keeping a stable,predictable investment environment and achieving several objectives of reform.