For 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 for methyl orange catalytic degradation were investigated. The results showed that the α-Fe2O3 acquired 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°C. And 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 best removal of methyl orange reached at 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.