Nucleocapsid, nucleocapsid protein, is an important structural protein of novel coronavirus SARS-CoV-2, which is responsible for wrapping the virus RNA genome and then assembling virus particles. Nucleocapsid has two domains: NTD and CTD, in which CTD has two functions: binding to RNA genome and forming homodimer. There are many positively charged amino acid residues on the surface of CTD protein, which can bind to the negatively charged RNA genome by charge interaction. The two molecules of CTD can form a homodimer through the hydrophobic interaction between β-strands, and then form a higher-order polymer complex. Therefore, CTD plays an important role in the process of virus replication and assembly. In the process of novel coronavirus SARS-CoV-2 therapeutic drug development, CTD inhibitors have become a hot target for drug screening. At the same time, the antigen detection kit developed for CTD provides a more efficient and accurate detection method for SARS-CoV-2 detection.