This study focused on investigating the effect of substrate proportion of vinegar residues and fermentation time on protein enrichment. With optimized proportion of 40% vinegar residues mixed with 20% corn skin and 40% sesame meal, the solid-state fermentation was carried out for a duration of 40 h. The count of yeast cells reached up to 121×108 per gram of product obtained, and crude protein of the fermented substrate increased to 33.5% from the original 19.6%, an increase of 70.91%.