To investigate the lipid-lowering effects of Sanhua Tea, a ready-to-drink Sanhua Tea made from rose, jasmine, citrus aurantium, lotus leaves, and Chuanxiong was prepared as the experimental material. The lipid-lowering efficacy of Three-Flower Tea was studied through in vitro experiments, and its application in black tea milk tea was explored to determine the optimal formula for lowsugar, low-fat milk tea. Cholesterol esterase inhibition rate, pancreatic lipase inhibition rate, and sodium cholate absorption efficiency were selected as indicators to evaluate the lipid-reducing activity of Sanhua tea in vitro. By adding Sanhua tea to low-sugar milk, the optimal formula of low-sugar and low-fat milk tea was obtained by combining fuzzy mathematical sensory evaluation, single factor testing, and response surface testing. The results showed that Sanhua tea significantly strongly inhibited cholesterol esterase (87.11%) than pancreatic lipase (53.91%) and sodium cholate absorption efficiency (3.97%). The optimal formula for low-sugar and low-fat milk tea composed of 0.35% instant black tea, 6.00% Sanhua tea, 35.00% milk, 4.45% honey and xylitol (1.5:1), and 0.10% sucrose ester and monoglyceride (1:1). The main physicochemical properties of the low-sugar, low-fat milk tea were analyzed. The total sugar, crude fat, crude protein content, and stability coefficient were 0.152 mg/g, 0.010 mg/g, 0.455 mg/g, and 1.048, respectively. This study confirmed that instant Sanhua tea effectively inhibits cholesterol absorption in vitro and has potential lipid-reducing effects. These findings provide theoretical basis and data support for the development of new low-sugar, low-fat milk tea products with desirable sensory qualities and health benefits.