The inlet of the high-pressure air cooler is filled with not less than 5% water of the processing raw materials. According to relevant inquiries, the water injection at the inlet of high-pressure air cooler has a great relationship with the processing raw materials. The first injection amount is about 5%, the ammonia content in circulating hydrogen is kept below 10ppm, and the total concentration of sulfur and ammonia compounds in highly acidic water should be kept below 8% through reactive injection to reduce the corrosion of H2S aqueous solution to heat exchangers and air-cooled tube bundles.