Abstract: The spread of multidrug-resistant gram-negative bacteria, particularly the global dissemination of carbapenem-resistant Enterobacteriales, has posed one of most severe challenges to the public health in 21^st century. Colistin, as a "last-resort" antibiotic, has been reintroduced into clinical treatment, however, the drug resistance to colistin was increasingly severe with its extensive clinical application. Given the long cycle and high failure rate of development of novel drugs, there is an urgent need to put forward sensitization strategies capable of rapidly restoring colistin's antibacterial activity. The research progress in colistin sensitizers was systematically reviewed in the article, and their sensitization mechanisms were summarized into six categories: targeting colistin resistance genes and related regulatory systems, enhancing permeability of cell membrane, disrupting lipid metabolism, inhibiting efflux pump systems, inducing the production of reactive oxygen, and synergizing with bacteriophages or nanomedicine formulations. The sensitization magnitude, cytotoxicity, and in vitro/in vivo efficacies were further highlighted and compared with representative molecules, while the potential of transforming already-marketed drugs to novel therapeutic applications was explored.