The 1982 United Nations Convention on the Law of the Sea (UNCLOS) was adopted on 30 April 1982 and opened for signature on 10 December 1982. UNCLOS entered into force on 16 November 1994. In terms of content, UNCLOS 1982 comprehensively regulates international legal issues on seas and oceans, and is the most important international legal basis for countries to establish and exercise sovereignty, sovereign rights, jurisdiction; rights, obligations and other freedoms in the process of exploiting, managing and using seas and oceans for peaceful purposes. Therefore, UNCLOS is considered the “Constitution of the Seas and Oceans” of the international community, the second most important global international treaty after the United Nations Charter, UNCLOS is the legal basis for all actions and cooperation at the national, regional and global levels to “resolve all issues related to the law of the sea” and “establish a legal order at sea.” However, in the face of the constant changes in science and technology, the need to exploit and use marine resources, climate change, international geopolitics, etc., UNCLOS also needs to change to continue to improve and promote its universal international legal value in the present and the future. Based on the above practice, this article will study and clarify three challenges to improve UNCLOS 1982.