[Objective] The comprehensive effects of different intercropping methods of four perennial forage grasses on growth， photosynthesis， and soil moisture in the Loess Plateau were analyzed. Screening of the optimal intercropping method was also done to provide theoretical support for establishing high-yield， efficient， and sustainable artificial grasslands in the Loess Plateau. [Methods] Four perennial forage grasses （Medicago sativa， Bromus inermis， Elymus dahuricus， and Astragalus adsurgens）， with intercropping of one （n=4）， two （n=4）， three （n=2）， and four （n=1） species were established to analyze the growth， photosynthetic， and water use characteristics of the forages under the different mixture patterns. [Results] The total relative yield of all intercropping treatments exceeded one. The intercropping treatment of M. sativa and B. inermis achieved a total relative yield of 2.08. This treatment increased the biomass of B. inermis and M. sativa to 279.1% and 132.4%， respectively， compared to their monoculture. Intercropping of M. sativa and B. inermis significantly increased the net photosynthetic rate and transpiration rate of M. sativa （p<0.05）. There was no significant effect on the net photosynthetic rate of B. inermis， but leaf water use efficiency increased significantly （p<0.05）. This intercropping also increased the water content of the deep soil. Entropy-weighted TOPSIS evaluation revealed that the M. sativa and B. inermis intercropping produced the best comprehensive effects in terms of forage yield， growth physiological characteristics， water and soil resource utilization efficiency， and soil water storage capacity. The comprehensive effect of gramineous monoculture was the worst. [Conclusion] Reasonable intercropping configurations can optimize vertical soil moisture distribution and enhance forage net photosynthetic rate， thereby improving system productivity and water utilization. Intercropping of M. sativa and B. inermis could effectively enhance production capacity and water use efficiency， providing valuable practical guidance for optimizing forage intercropping systems in semi-arid regions of the Loess Plateau.