To address the defect of low catalytic performance due to the two-phase mass transfer resistance in heterogeneous photo-Fenton, a hydrothermal method was used to prepare catalysts α-Fe₂O₃ that exposed different ratios of crystal plane {110}/{113}. α-Fe₂O₃ was characterized by XRD, TEM/HRTEM, FTIR and UV-vis DRS. The effects of H₂O₂ concentration, catalyst dosage, initial concentration of methyl orange and initial pH on α-Fe₂O₃ on methyl orange catalytic degradation were investigated. The results showed that the α-Fe₂O₃ achieved the best catalytic performance when the concentration of precursor FeCl₃·6H₂O was 33 mmol/L, the dosage ratio of FeCl₃:6H₂O:NaH₂PO₄:NaF was 1:1:15, and the reaction temperature was 180℃. Moreover, at the H₂O₂ dosage of 20 mmol/L, catalyst dosage of 200 mg/L, initial methyl orange concentration of 40 mg/L and initial pH of 5, the removal of methyl orange was the best, reaching 97.83% in 60 min. The catalyst exhibited good stability after consecutive degradation cycles. The H₂O₂ consumption analysis and free radical trapping experiment results showed that hydroxyl radicals and photo-generated holes played a key role in the catalytic degradation process, while superoxide radicals had less effect.