Abstract: As an excellent corrosion protection material for pipeline the coal tar enamel was widely used. Manual coating in construction will bring the problems of long operating time, environmental pollution, poor coating quality, and waste of labours, materials, fiancial, adopting mechanized automaticly produstion is obviously in advantage. A comparison with two methods in view of clearing pipe surface, spray priming, overlaying and wrapping can conclude that mechanized automaticly coating is not only high in production efficiency, well in surface cleaning quality, even in priming thickness, quick in drying, enable to ensure close cohesion between overlay and wrapping layer, but also fast cooling and curing for overlay coating, special for corrosion protection quality at interface of pipeline end face. So mechanized automatic coating in the optimal method for coal tar enamel coating of pipeline in construction.