Based on the results of sensory evaluation， single factor test was used to determine the koji making strains and the formula of raw materials for good flavor. The results showed that when koji-making strains were Aspergillus oryzae and Saccharomyces cerevisiae， raw materials were 80% egg liquid and 20% black bean powder， the flavor of koji was the best， and it had olive and vegetable flavor and slight salted egg yolk flavor. The time of steaming， the moisture content and the time of koji making were selected as independent variables， the activity of protease was taken as an index， Box-Behnken was used to optimize the koji-making process. The results showed that when the steaming egg curd time was 41 min， the moisture content in egg curd was 66.1%， and the koji ferment time was 50 h， the highest protease activity in egg koji was 5 797 U/g. The study has found a feasible scheme for the development of egg sauce products.