In order to provide theoretical basis for high yield and good quality cultivation of Fagopyrum tataricum in the Loess Plateau, we determined the effects of combining different nitrogen (N application rates of 0 g/kg, 0.1 g/kg and 0.2 g/kg) and phosphorus fertilizer (P₂O₅ application rates of 0.1 g/kg and 0.2 g/kg) conditions on the root physioecological indices and yield during the growing period of F. tataricum under experimental pot conditions. The results showed that: (1) under equal phosphorus fertilizer treatments, plant height, stem diameter, shoot dry weight, main root length, root surface area, root volume, root average diameter, root dry weight and seedling index initially increased and then decreased with increasing nitrogen application rate while root shoot ratio decreased initially and then increased with increasing nitrogen application rate. Chlorophyll content, root activity, acid phosphatase activity, soluble protein content, plant N accumulation show the parabola changes with the increase of nitrogen application rate. Root NR activity and plant N content increased with increasing nitrogen rate while SOD, POD activities and MDA content in root, soluble sugar content and free proline content decreased initially and then increased with increasing nitrogen application rate. Weights per plant and 100seed weight initially increased and then decreased with increasing nitrogen application rate. (2) Under equal nitrogen fertilizer treatments, root Apase, SOD and POD activities, soluble sugar, soluble protein and MDA contents decreased with increasing phosphorus application rate. The other above indices increased under high phosphorus treatment compared with low phosphorus treatment. (3) Among the three nitrogen levels, yield of F. tataricum was the highest under 0.1 g/kg nitrogen application. It increased respectively by 7.04% and 37.40% compared with 0 g/kg and 0.2 g/kg nitrogen treatments under low phosphorus condition. It also increased respectively by 14.73% and 68.26% compared with 0 g/kg and 0.2 g/kg nitrogen treatments under high phosphorus condition. In addition, the yield of F. tataricum was higher in high phosphorus treatment. It also increased, respectively by 15.96% and 42.00% compared with low phosphorus treatment under equally nitrogen fertilizer treatment. (4) In this study, reasonable application of nitrogen and phosphorus fertilizer showed a positive additive effect, but overapplication of fertilizer could reduce yield. F. tataricum was more suitable for production at suitable nitrogen fertilizer (0.1 g/kg N application) and high phosphorus fertilizer condition (0.2 g/kg P₂O₅ application).