Enhancing the speed of microbial antimicrobial susceptibility testing (AST) is an urgent requirement for effective patient treatment, rational use of antimicrobial agents, and mitigating the development of microbial resistance. Novel rapid AST methods primarily involve advancing the observation timepoint of microbial growth. By capturing changes in microbial quantity, morphology, and metabolism during the early incubation phase—when microbial growth is invisible to the naked eye—these techniques utilize various devices and technologies to determine the resistance relationship between microorganisms and antimicrobial agents. This article reviews the current advancements in rapid AST from four perspectives: (1)monitoring microbial growth phenomena, (2)fluorescence labeling to indicate cellular activity, (3)detecting cellular metabolic states and products, and (4)matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based rapid AST. The aim is to provide a reference for clinical microbial resistance management.