In this paper, the authors studied the effect of AlPO₄ content on the formation of iron minerals in the cultures of A. ferrooxidans HX3, and characterized and analyzed the structures of the obtained corresponding precipitate products. The results showed that the addition of AlPO₄ had little effect on Fe²⁺ oxidation during bacterial cultivation, but it could promote Fe³⁺ hydrolysis and formation of the initial iron mineral phase and accelerate transformation of jarosite. Under the higher Al/Fe mole rates of 0.04~1, schwertmannite and jarosite could be formed. Also, iron phosphate could be formed in cultures with Al/Fe mole rates of 0.4 and 1. The higher Al/Fe mole rate and phosphate content are conducive to the formation of iron phosphate.