The solid acid catalyst (HClO4/SBA-15) was prepared by using a molecular sieve SBA-15 supported perchloric acid, and characterized by infrared spectroscopy. A method for the synthesis of ornidazole with solid acid HClO4/SBA-15 as catalyst, 2-methyl-5-nitroimidazole and epichlorohydrin was developed. The influences of different catalytic dosage, reaction time, reaction temperature and different solvents on the conversion were investigated. The optimum conditions showed that when the amount of 2-methyl-5-nitroimidazole: HClO4 / SBA-15 was equal to 5:3, and the reaction was carried out at 0°C for 8h with the reaction of isopropanol as the solvent, the conversion of 2-methyl-5-nitroimidazole could reach to 76.3%, Purity of 99.8%. The product was identified by nuclear magnetic resonance spectroscopy and mass spectrometer. The results showed that the quality of ornidazole was consistent with the quality standard of pharmacopoeia. The catalyst can be reused and the conversion rate is still 65.8% for the third use.