As a food processing technology with a long history, microbial fermentation has shown its unique advantages in safety control and quality extension in the modern food industry. The fermentation process produces antibacterial substances such as organic acids and bacteriocins through microbial metabolism, which can effectively inhibit the growth and reproduction of pathogenic bacteria and spoilage bacteria. At the same time, the reduction of pH value and the regulation of water activity caused by fermentation have created environmental conditions that are not conducive to the growth of microorganisms for food. In many fields, such as dairy products, meat products, fermented beverages and cereal and vegetable products, fermentation technology has achieved large-scale application, significantly improving the microbial safety and shelf life stability of products. By optimizing strain selection and controlling process parameters, fermentation technology is gradually replacing some chemical preservatives, providing a more natural and healthy preservation solution for the food industry, which has broad application prospects and research value.