Miroecologics have a variety of functions such as regulating human intestinal microecology, immune enhancement, antitumor, anti-aging, etc and are important elements of functional dairy products. Application of probiotics in dairy products has very important significance in enriching the functions of dairy products, guiding the healthy diet and promoting the development of the dairy industry. Research and development of dairy products rich in probiotics, prebiotics and/or synbiotics will become the dominant direction of the development of dairy products. This paper introduces recent applications of microecologics in dairy products with emphasis on key technologies.