Abstract: The fouling mechanism of pipeline is studied in the paper. The result shows that if the medium contains high water rate, more germ, high mineral degree, and dissolved with certain amount of corrosive gas such as hydrogen sulfide, carbon dioxide and oxygen, and is deposited with paraffin, pipeline fouling will be inevitable. Such factors working on pipeline fouling as temperature, pressure, velocity of flow, pH value and so on are analyzed. Some measures are proposed for protecting pipeline from fouling and the methods such as scale removing by chemical and mechanical means are put forward.