To clarify the effects of intercropping and phosphorus fertilizer application on the inorganic phosphorus forms of low phosphorus red soil and to promote the efficient useof phosphorus fertilizer in acidicsoil，two croppingpatterns，maizemonocropping(MM)and maize//soybean intercropping(MI)，were used to investigate the effects of intercropping on the inorganic phosphorusforms of red soil at four levels of phosphorus application(P 2O50，60，90，120 kg·hm -2，marked asP0，P60，P90，P120，respectively). The characteristics of inorganic phosphorus forms in the rhizosphere soil of maize// soybean intercropping was studied and the effects of intercropping on maize yield andsustainability，phosphorus uptakeand phosphorusbalance，and soil inorganic phosphorus forms were explored in red soil. The results showed that maize grainyield and its sustainability index(SYI)，phosphorus uptake increased with the increase of phosphorus application level and reached the maximum at P90 level. The inorganic phosphorus forms of the low phosphorus red soil were dominated by O-P and Fe-P，which accounted for 71.44%-80.18% of the inorganic phosphorus pool. The content and proportion of Fe -P and Al-P in red soil were significantly increased by applying phosphorus fertilizer. Maize//soybean intercropping significantly increased maizeyield，promoted phosphorus absorption and utilization，reduced soil phosphorussurplus，and significantly reduced the contents of O-P，Fe -P and Al-P in red soil. Compared withmonocropping，under theP60，P90 and P120levels， intercropping grain yield was significantly increasedby66.70%，52.44% and74.14%，SYI was significantly increasedby55.31%，42.18%and78.00%，and phosphorus uptake wassignificantly increased by61.97%，48.67%and74.33%，respectively，and soil phosphorus surplus was significantly decreasedby33.39%，27.27% and17.06%，respectively.Compared withmonocropping，available phosphorus content in intercropping red soil was notsignificantlydifferent，while O-P and Al-P contents atP0，P60，P90，P120 levels were significantly decreasedby20.62%，16.79%，16.62%，18.48% and21.98%，21.08%，20.19%，20.18%，respectively. The Fe -P content wassignificantly decreased by19.37%，15.78% and 17.72% inP60，P90 and P120levels，respectively. There was no significant difference in Ca-P content betweenintercropping and monocropping red soils with low phosphorus supply(P0 andP60). At P90 and P120levels，Ca -P content in intercropping red soils were decreased by 23.50% and26.70%，respectively. Random forest model analysis showed that Fe-P and Al-P were the key inorganic phosphorus forms in intercropping red soil. The total variance interpretation ofintercropping increased by 7.95% compared with monocropping. Inconclusion，rational intercropping in low phosphorus red soil can increase the phosphorus uptake of maize by promoting the mobilization of insoluble inorganic phosphorus forms in redsoil，which has the potential to reduce soil phosphorus fixation and improve maize yield and sustainability.