With the rapid development of oil and gas pipelines in China，the diameter of pipelines has became larger，while the pipeline wall was down to thinner，but the quality ofpipeline joint has been a weak point of the whole corrosion protection system. In order to im.prove the protection，the technology of gas polarization was used in the East China-Russia nat.ural gas pipeline project（HeiHe-ChangLing），it was concluded that the adhesion between ep.oxy coatings and polyethylene layer of main pipeline was greatly enhanced，and the problem ofoverlap edge warping between epoxy coating and polyethylene layer of main pipeline was effec.tively solved.