Abstract: Through complete and systematic analysis on the function of 3-layer polypropylene coating for oil and gas pipelines, the authors consider that the 3-layer polypropylene coating is characterized by excellent refractory and anticorrosion performances among other coating materials, and this coating is especially available for the anticorrosion of oil pipeline under high temperature conditions, pipeline networks of urban heating system and chemical industry pipeline. But there are some defects in the material such as not applicable for cold regions where special materials and technologies shall be adopted for field joint coating and defects repair.