The potassium permanganate was used for manganese oxide catalyst with various methods and various processes, which manganese oxide wasused for removal of formaldehyde in flow gas. Experiments indicate that these catalyst materials are difference from each other because of raw materials used and pH values in catalysts preparation when used for formaldehyde removal. And when catalyst was prepared by using potassium permanganate and GLU or PEAunder different pH values respectively, it could have good performance in formaldehyde oxidizing purification. In this thesis, when the ratio of potassium permanganate and GLU was 5:1 for catalyst preparation, and 5 mL of nitric acid was added, the formaldehyde elimination efficiency could be maintained at 100% longer than 600 minutes. And when the ratio of potassium permanganate and PEA was 10:1 for catalyst preparation, and 5 mL of nitric acid was added, the formaldehyde elimination efficiency could be maintained at 100% longer than 705 minutes.