The thin-film dryer process calculation mathematical model was established, with 25% calcium propionate as the research object, using the numerical simulation software MATLAB, drying rate and drying length was obtained and the influence of feed temperature, rotate speed, feed rate, and heating temperature was also discussed. The results showed that feed rate and heating temperature had a great influence on drying rate and drying length, while feed temperature and rotate speed had less influence on drying rate and drying length, which provided the basis for calcium propionate drying.