A pot experiment was conducted to investigate the effects of four amendments (biochar，biochar compound fertilizer，swine manure and lime) and their application rates on red soil pH，exchangeable acidity，soil nutrients，and maize growth.Ten treatments were included:chemical fertilizers only (CK)，biochar at levels of 1% and 3% (B1，B3)，biochar compound fertilizer at levels of 1% and 3% (BF1，BF3)，swine manure supplied 20% (M20) and 40% (M40) of total N，lime at levels of 0.02% and 0.04% (L0.02，L0.04)，M20+L0.02 (M20L0.02).The results showed that the BF1 treatment significantly reduced soil pH by 0.19 units compared to the CK treatment，while the BF3，biochar，swine manure and lime treatments maintained soil pH；The B3，BF1，M40 and L0.04 treatments significantly decreased soil exchangeable acidity.The BF1 and BF3 treatments increased soil available nitrogen by 83 and 305 mg/kg，respectively，relative to CK；The M40 treatment significantly increased soil available phosphorus by 4.1 mg/kg，while the M20 treatment had no change.The B1，B3 and BF3 treatments increased soil available potassium by 46，138 and 171 mg/kg，respectively，compared to CK.Above-ground biomass was significantly reduced by 37% in the BF3 treatment compared to CK，and the highest value was observed in B3 treatment，which was significantly higher than that from BF3，M20，L0.02，L0.04 and M20L0.02 treatments.Comparing with CK，the BF3 treatment significantly increased maize nitrogen uptake by 32%.The results showed that four improved materials could improve the acidity of red soil；Based on crop growth and nutrient balance，biochar can be used as a material to improve the acidity of red soil，which can appropriately reduce the input of potassium fertilizer.Carbon-based fertilizer can reduce the input of chemical nitrogen and potassium fertilizer，and swine manure can reduce the input of chemical phosphorus fertilizer.