To explore the effects of unconventional feed combinations on the growth and production, digestion and metabolism, and rumen fermentation of dairy cows, three different dairy cows were selected for the experiment. They are Holstein cows with permanent rumen fistula, 3 primiparous cows and 6 multiparous cows. The cow diet was prepared according to the ratio of 0% CGF, 7% CGF and 11% CGF. Part of alfalfa hay in the conventional diet was replaced by CGF and Leymus chinensis. The study analyzed the feed intake, digestibility, lactation performance, blood biochemical indicators, rumen degradation parameters, rumen microorganisms and other indicators of dairy cows. The nutritional composition, digestible nutrients and absorbable protein content of CGF, L. chinensis and alfalfa hay were verified. The feed economic benefits of different unconventional feed combinations were also investigated. The protein small intestine digestibility of CGF was higher than that of alfalfa hay. tdFA, NEm, NEg, and DEp were significantly higher than those of L. chinensis and alfalfa hay (P<0.05). Under the three CGF ratios, the nutrient intake and digestibility of the CGF-11% group were the highest (P<0.05). The S, Kd dry matter degradation rate and crude protein degradation rate of the CGF-11% group were significantly higher than those of the CGF-0% group and CGF-7% group (P<0.05). The CGF-11% group had the highest total output value and economic benefits, 119.057 ¥/d and 68.62 ¥/d respectively. To sum up, it was feasible to use the combination of CGF and L. chinensis to replace part of alfalfa hay in cow feed. This method could effectively promote rumen degradation and nutrient absorption in dairy cows. And it can improve the production and economic benefits of dairy farming. This is of great value for adjusting the structure of aquaculture feed in China.