With beef enzymolysis liquid as raw material, the flavor essence of braised beef brisket with tomato is prepared through thermal reaction. By exploring the influence of different enzymatic hydrolysis on flavor essence through single factor and orthogonal experiments, and combining with the sensory evaluation results & degree of hydrolysis, the optimal enzymatic hydrolysis conditions are found. Flavourzyme is the best enzyme for this flavor essence, and the optimal reaction conditions are as follows: material ratio is 3∶4; enzyme dosage is 0.10%; reaction temperature is 45℃; reaction time is 3h; under the natural pH. Degree of hydrolysis is 4.45%. Moreover, in this condition braised beef brisket with tomato flavoring has strong aroma, lasting aftertaste and high similarity to the dish.