Understanding the effects of straw biochar on soil organic phosphorus fractions and distribution in lime concretion black soil is of great significance to analyze the soil phosphorus cycle mechanism and excavate the availability of soil phosphorus pool. In this study, the effects of no fertilization (CK), conventional fertilization (NPK), chemical fertilizer and one-time addition of wheat straw biochar (BC₆, BC₁₂, BC₃₆ and BC₄₈) on crop yield, soil physicochemical properties and organic phosphorus components were analyzed based on field experiments on lime concretion black soil. The results showed that, compared with NPK treatment, increased application of straw biochar could guarantee wheat and maize yields, significantly increase (P < 0.05) the soil organic carbon, total nitrogen and pH, and improve the soil fertility and alleviate the soil acidification. The proportion of organic phosphorus in lime concretion black soil was mainly medium labile organic phosphorus (37.4% - 45.4%). The proportion of organic phosphorus in lime concretion black soil was different with different application amount of straw biochar. The contents of labile soil organic phosphorus in BC₆, BC₁₂, BC₃₆ and BC₄₈ treatments were 11.4, 10.7, 9.2 and 9.3 mg·kg^-1, respectively, which were 8.8%, 14.4%, 26.4% and 25.6% lower than that in NPK treatment, respectively. The difference was striking (P < 0.05). There was a significant negative linear correlation between the soil labile organic phosphorus content and the application amount of biochar (R² = 0.881 6, P < 0.05). Increasing straw biochar application processing (BC₆, BC₁₂, BC₃₆ and BC₄₈) and the proportion of soil labile organic phosphorus in NPK treatment were significantly decreased (P < 0.05), suggesting that increasing straw biochar could effectively enhance the level of the soil fertility, soil acidification