The aim of this study was to screen the fine fermentation strains of wheat distiller's grains and optimize its solid-state fermentation technology to improve its feed quality. The content of acid soluble protein in the fermentation product was the main factor to evaluate the fermentation of wheat distiller's grains supplemented by wheat middings. The optimal combination of strains that saved in the lab were studied by using a single-factor test. And then optimize the fermentation substrate ratio and solid-state fermentation conditions (inoculation amount, fermentation temperature and fermentation time). On the basis of single factor experiment, response surface methodology was used to optimize the solid-state fermentation conditions. The optimum combination of strains was obtained by Lactobacillus R-02 and Bacillus Subtilis KG109. The best fermentation substrates matrix proportion were as follows: wheat distiller's grains was 38%, wheat middings was 62%. The optimum solid-state fermentation conditions were as follows: inoculation amount was 1.22%, fermentation temperature was 33.45 ℃, fermentation time was 6.78 days. Under these fermentation conditions, acid soluble protein was 4.33%. After optimization of the fermentation of wheat distiller's grains, feed quality has been significantly improved.