Abstract: The almond milk and bovine milk were used as raw materials and blended in a certain mass ratio to form an almond-bovine milk mixture, which was homogenized, sterilized, inoculated and fermented to obtain the composite fermented milk. By evaluating the sensory characteristics, texture characteristics, rheological properties, and viable bacteria count of the fermented milk, the influence of the ratio of almond milk to bovine milk on the quality characteristics of the composite fermented milk was explored, aiming to solve the problems of insufficient acidity, poor flavor, and poor water-holding capacity of single-plant-based almond fermented milk. The research results showed that as the ratio of almond milk to bovine milk increased, the coagulation time of the composite fermented milk gradually shortened, its total solids content and acidity value decreased, pH and chromaticity value increased, while the soluble protein content, water-holding capacity, texture characteristics and rheological properties of the composite fermented milk initially increased and afterwards reduced, and the whey separation rate firstly decreased and then increased (P<0.05). Compared with single cow fermented milk and almond fermented milk, when the ratio of almond milk to bovine milk was 50:50, the sensory score of the composite fermented milk was the highest, and its microstructure was the highest compact. At this time, the soluble protein content of the composite fermented milk was the highest, its water-holding capacity was the largest, its whey separation rate was the lowest, its viscosity and elasticity were the best, and its viable bacteria count was the most. Compared with the single almond fermented milk, the composite fermented milk obtained at a ratio of almond milk to bovine milk of 50:50, made its sensory score increased by 20.38%, its soluble protein content increased by 50.65%, its water-holding capacity increased by 29.66%, and its whey separation rate reduced by 62.62%. In conclusion, the composite fermented milk of almond milk and cow's milk had better quality characteristics than the single almond or cow fermented milk. This study provides the basic data support for the development of unique-flavored and nutritionally comprehensive composite fermented milk products, and has the certain guidance significance for enriching the varieties of composite fermented milk.