Abstract: On April 13, 2021, Japan decided to discharge nuclear waste water from the Fukushima Daiichi nuclear power plant into the sea. This news has aroused the close attention of people all over the world. The discharge of nuclear waste water into the sea will have a serious impact on the marine environment and the public. This paper reviews the types, contents, detection methods, and possible hazard of the radionuclides in the nuclear waste water from Fukushima Daiichi nuclear power plant in Japan, and puts forward some constructive suggestions for this incident.