Abstract: Cross-linking mass spectrometry (XL-MS) technology has become a key tool for identifying protein-protein interactions (PPIs) and revealing the protein structures in living cells, tissues, or organelles. The XL-MS technology has demonstrated remarkable superiority compared with conventional methods for studying PPIs and protein structures. In the past few years, new cross-linker structures have been arising continuously. They have not only broadened the range of cross-linking reactions but also provided additional methods for the enrichment of cross-linking peptides. Moreover, owing to the advancement of computer software and artificial intelligence, cross - linking data search engines and visualization software have also been enhancing the speed and accuracy of cross-linking peptide identification. The evolution of cross-linkers and cross-linking peptide search engines has promoted the application of the XL-MS technology in the research on protein-protein interactions (PPIs) within organelles and even living cells and in the analysis of protein structures.