Since Japan announced its plan to discharge Fukushima nuclear wastewater into the sea on April 13, 2021, the discussions on the hazards and illegality of this act have never stopped. In this discharge crisis, countries neighboring Japan are direct stakeholders, so the coping strategies they will adopt particularly attract worldwide attention. The paper focuses on the Challenges of Fukushima Nuclear Wastewater Discharge into the sea and discussing China's responses to Fukushima nuclear wastewater discharge into the sea from the perspective of China's right-safeguarding strategies. It has reached the following conclusions: once Fukushima nuclear wastewater is discharged into the sea, it will result in a serious hazard and cause social and economic impacts on all aspects; the Japanese government's decision and act to discharge Fukushima nuclear wastewater into the sea are against laws; the legal basis for China to safeguard its rights includes China's domestic laws and Japan's domestic and international laws. Regarding the right-safeguarding strategy, China can act on the domestic and international levels to defend its rights and interests and safeguard the security of the ocean environment and humans.