Abstract: Deep-sea polymetallic nodules, as the most technically exploitable marine metal mineral resources, are rich in critical elements such as iron (Fe), manganese (Mn), and cobalt (Co), with reserves and abundance demonstrating significant mining potential. Currently, under the coordination of the International Seabed Authority (ISA), authorized countries have initiated geological and mining exploration research in polymetallic nodule regions. Due to the high difficulty and cost associated with deep-sea sampling and operations, it is the key to realize the mineral exploration and value evaluation of polymetallic nodule area to explore the polymetallic nodule mineral resources efficiently and accurately. This study systematically collates and analyzes cutting-edge domestic and international methods for polymetallic nodule reserve estimation. It begins with a review of the distribution and metallogenic mechanisms of polymetallic nodules, followed by a comparative analysis of mainstream contact-based and non-contact reserve assessment methods. Finally, it summarizes and critiques the advantages and limitations of existing polymetallic nodule reserve assessment methods, providing references for future research directions in this field.