Milk tea beverage is a drink widely loved by consumers. The astringency caused by the rich tea polyphenols in the tea soup is one of the key factors affecting the sensory quality of milk tea beverage. Existing research has shown that milk components, such as milk proteins, can reduce astringency. Milk fat, an important component in cow's milk, is composed of milk fat globules. However, the effect of its content and structure on astringency in milk tea systems remained unclear. It was aimed to investigate the impact of milk fat content and fat globule structure on astringency in milk tea systems. Firstly, it used descriptive sensory evaluation to explore whether milk fat and fat content affected the astringency of milk tea system. Next, three types of milk fat droplets with the same fat content but different structural characteristics were constructed by adjusting the heating intensity and homogenization pressure: milk fat droplet C, milk fat droplet T and milk fat droplet H, and the particle size,ζ-potential, microscopic structure, milk fat globule membrane protein content and composition, and milk fat globule membrane phospholipid content were measured, which characterized the characteristics of milk fat globules. Then different milk fat droplets were added to the simulated milk tea system to conduct sensory evaluation of astringency intensity, and quantify astringency through fluorescence spectroscopy analysis. The results showed that when the milk fat content reached above 4 g/(100 mL), the addition of milk fat can significantly reduce the astringency level in milk tea. In addition, changing the particle size and membrane structure of milk fat globules also had a significant impact on the astringency of the milk tea system. Compared with the other two milk fat droplets, the fat globule size in milk fat droplet H was the smallest (0.49 μm), the protein content per gram fat globule membrane was the highest (12.60 mg), and the astringency was the weakest. Milk fat droplet T had the largest particle size (4.20 μm), the lowest protein content per gram fat globule membrane (4.12 mg), and a strong astringency. Therefore, milk fat content, particle size and membrane structure would affect the astringency intensity of milk tea system. Smaller milk fat globule size and more milk fat globule membrane interface proteins had the greatest effect on reducing the astringency intensity of milk tea system. It was confirmed the impact of milk fat on the perception of astringency in the milk tea system, laying a theoretical foundation for the development of green and healthy milk tea drinks with a smoother taste.