Abstract: The increasingly severe of soil acidification seriously affects crop growth, thereby reducing their yield and quality. Unreasonable use of chemical fertilizers in agriculture may exacerbates soil acidification. In this study, Mg/Fe-layered double hydroxides modified phosphorus-intercalated biochar composite (MgFe-LDH/BC-P) was mixed with chemical fertilizers at different proportions (1‰, 2‰, 3‰, and 6‰), and then applied as a soil conditioner in maize pot experiments to investigate its remediation effect on acidified soil and its impact on nitrogen utilization efficiency. The results demonstrated that after the application of MgFe-LDH/BC-P mixing with chemical fertilizers, soil pH, electrical conductivity (EC), organic matter content, and available phosphorus content were significantly increased, while exchangeable acidity was reduced. The plant height, stem diameter, Relative chlorophyll content (SPAD), and accumulation of nitrogen, phosphorus, and potassium in maize plants also increased, and these were significant changes with the increase of MgFe-LDH/BC-P application proportion, effectively improving the nitrogen utilization efficiency. Additionally, the mixture of MgFe-LDH/BC-P and chemical fertilizers improved soil microbial community structure and enhanced Alpha diversity. In conclusion, MgFe-LDH/BC-P applied to acidified soil can effectively improve the physicochemical and microbial properties of acidic soil. However, its long-term alleviation effect and mechanism on acidified soil require further investigation.