Kluyveromyces marxianus is a GRAS-classified fungal microorganism, renowned for its capacity to generate both conventional and specialized enzymes, as well as its function as a vector for the expression of specific enzymes. In the food industry, K. marxianus serves as a fermentation agent capable of effectively controlling the fermentation process and significantly enhancing the quality of fermented foods. This article systematically analyzes the microbiological characteristics of K. marxianus, reviews its application in the fermentation of products such as fruits and vegetables, dairy, grains, meat products, and alcoholic beverages, and explores its potential application in the future food industry.