In order to solve the problem that excessive accumulation of phosphorus in the soil of intensive facilities restricts the sustainable development of farmland, different types of soil conditioners were used to carry out pot experiments to study the dry matter accumulation, phosphorus uptake and soil phosphorus morphological changes of waxy maize. The results showed that the growth of maize in the biochar 70% + alum 30% treatment was the best, and the highest pot dry biomass was 44.6 g/plant, which was significantly higher than that of the control treatment 19.57%. The contents of total phosphorus and water-soluble phosphorus decreased to varying degrees after the application of conditioner compared with before planting. In terms of changes in soil inorganic phosphorus composition, 100% alum and 100% biochar treatments increased the content of slow-acting phosphorus sources, and 70% biochar + 30% alum treatment significantly increased the content of fast-acting phosphorus sources. Biochar 70% + alum 30%, biochar 30% + humic acid 30% + alum 30% treatment could effectively inhibit the activity of soil alkaline phosphatase and inhibit the mineralization of soil organophosphorus. On the whole, the biochar 70% + alum 30% treatment had good comprehensive performance in releasing soil potential phosphorus sources, improving soil available phosphorus sources, promoting crop phosphorus absorption, and improving crop dry matter quality accumulation.