Abstract: Desmodium styracifolium and Polygonum multiflorum were used as experimental materials, the effects of the intercropping density and harvest period on the quality and yield of Desmodium styracifolium were studied by using multivariate statistical analysis methods, in order to establish a suitable intercropping model of Desmodium styracifolium and Polygonum multiflorum and promote the development of ecological planting.The results showed that the planting density of Polygonum multiflorum had no significant effect on the stem-to-leaf ratio, dry weight, yield and extract content of Desmodium styracifolium;the content of total flavonoids and inorganic elements of Desmodium styracifolium showed an upward trend, and the content of schaftoside showed a downward trend; under the same Polygonum multiflorum intercropping density, with the decrease of the planting density of Desmodium styracifolium,the agronomic traits, leachings, total flavonoid content and B,Mn, Fe, Zn and other 9 elements showed a trend of first increasing and then decreasing.The stem-to-leaf ratio, dry weight per plant and the contents of Ca, Ni, Mo and Sn were increasing.The agronomic traits, yields, active ingredients and inorganic element content of Desmodium styracifolium were comprehensively analyzed, and the yield and quality of Desmodium styracifolium were harvested at an intercropping density of 60 cm×40 cm between Polygonum multiflorum plants and 40 cm × 50 cm after colonization, while time was 218 days, the yield and quality were the best.