Abstract: In order to study the effect of millet flour size on the quality of millet cake, the millet flour was divided into four grades of 60~80 mesh, 80~100 mesh, 100~120 mesh and over 120 mesh, and its water-holding, gelatinizing properties and color properties of millet flour were determined. The specific gravity of batter, specific volume of cake, texture characteristics and sensory quality of millet flour cake were also investigated and their correlations and flavor substances were analyzed. The results showed that with the decrease of particle size, the specific gravity of batter and cake hardness increased, the specific volume decreased, and the sensory score increased first and then decreased, when the particle size was 80~100 mesh, the cake had the highest sensory score. Millet flour particle size was positively correlated with cake hardness and the specific gravity of batter;negatively correlated with cake elasticity. A total of 30 flavor compounds were identified in Millet and Lycium barbarum dregs cake, including alcohols, aldehydes, ketones, esters and alkane.