Abstract: Objective: To explore the conditions of embedding diacylglycerol (DAG) with sodium casein (SC) and nano cellulose cellulose (NCC) as wall materials and improve the quality of functional fermented dairy products.Methods: Using milk fat as raw material, DAG was prepared by enzymolysis reaction. Using SC and NCC as wall materials, oil in water DAG emulsion was prepared. The addition amount of SC and NCC, particle size and homogeneous pressure of the emulsion under optimal preparation conditions were screened, and rheological analysis, texture analysis and sensory analysis were conducted on soft cheese with DAG nano-emulsion added. The stability difference between them was investigated and soft cheese was prepared as a fat substitute. Results: The optimum conditions for preparing sodium caseinate cellulose DAG lotion by the high-pressure homogenization method were as follows: NCC content 1.5%, SC content 5%, core wall ratio 1:1, homogenization pressure 100 MPa. All lotions are oils in water with particle sizes between 100~240 nm. By analyzing the characteristics of soft cheese, with the addition of DAG lotion, the elasticity of soft cheese increased, and the hardness, consistency, and cohesiveness all increased at first and then decreased. When the addition of lotion was 2%, the sensory quality was significantly higher than in other groups. Conclusion: In the NCC content of 1.5%, SC content of 5%, core wall ratio of 1:1, under the conditions of homogenization pressure of 100 MPa, DAG could be effectively embedded, and the embedding rate could reach 77.9%. When 2% DAG lotion was added to soft cheese, the sensory quality of the soft cheese could be significantly improved.