In order to explore the strength characteristics of ecologically reinforced soil with plant shells, the authors conducted a series shear test study on the loess reinforced with different petal-shaped buckwheat husks. First, we carried out the tests on the basic properties of buckwheat husks and loess, and then divided the buckwheat husks, added the divided the buckwheat husks to the soil according to a certain mass ratio of buckwheat husks to dry soil, compacted them into specimens, and carried out direct shear tests. The research results showed that the change law of shear stress-shear displacement curve of buckwheat husk reinforced loess is basically the same as that of plain soil. The strength of the soil reinforced with buckwheat husks has been significantly improved, with a maximum increase of 23%. In terms of strength indicators, the main manifestation is that after reinforcement，the angle of internal friction of the soil has been greatly improved, with a maximum increase of 6.13°, while the cohesion has decreased to varying degrees, but the decrease is not much, within 8kPa. It was also found that when the addition rate of buckwheat husk was greater than a certain percentage, the strength of buckwheat husk reinforced soil was greater than that of plain soil, and the percentage was related to the splitting of buckwheat husk. When the buckwheat husk is used as a reinforced material, there is a limit reinforcement rate. When the reinforcement rate is less than the limit reinforcement rate, the shear displacement required for the buckwheat husk to function generally increases with the increase of the vertical pressure. When the reinforcement ratio is greater than the limit reinforcement ratio, the shear displacement required for the buckwheat husk to function roughly decreases with the increase of the vertical pressure，the limit value is also related to the splitting of the buckwheat husk. In comparison, natural buckwheat husks and two-petal buckwheat husks are more suitable as reinforcing materials.