This paper aims to explore the effect of coexistence of biochar and organic acids on soil microelement，and to provide a reference for improving the soil nutrition with the coexistence of biochar and organic acid in the future. Biochar was prepared from corn stalks，yellow-brown soils at different depths were collected，citric acid and malic acid were selected for experiment，and a total of 8 different treatments were set up, including the topsoil without or with the application of biochar plus citric acid treatment，the topsoil without or with the application of biochar plus malic acid treatment，the subsoil without or with the application of biochar plus citric acid treatment，and the subsoil without or with the application of biochar plus malic acid treatment. The results showed that：（1） Compared with the control group，the application of two organic acids increased the dissolution of Fe and Mn in soil，and the Fe and Mn content in citric acid treated soil solution was higher than that in malic acid treatment. （2） Due to the difference in the physical and chemical properties between the subsoil and the topsoil，the dissolution of Fe and Mn was affected，and the dissolution of Mn in the subsoil solution was higher，up to 0.34 mmol/L，while the dissolution of Fe in the topsoil solution was higher， up to 0.7 mmol/L； 3） 2% of biochar did not completely inhibit the dissolution of microelements by two organic acids. The conclusions indicate that organic acids can activate Fe and Mn in soil, and their activation effects are related to the type and concentration of organic acids metals and pH of soil. The application of biochar has limited ability to inhibit the activation of microelement in soil by organic acids.