Abstract: In order to solve the problem of internal corrosion of metal gathering and transportation pipelines in Qinghai oilfield, the internal corrosion prevention technology of epoxy coating by air delivery and extrusion was applied. By adding glass fiber and special additives, a glass fiber toughening coating and a special coating for 32 MPa high-pressure water injection were made. The coating had high corrosion resistance, adhesion and mechanical properties. The development and application of video endoscopy and internal detector had realized the transformation of internal extrusion coating construction quality inspection from port to interior. The construction process was optimized to form the process of “two-way sand blasting and rust removal” and “two-way squeeze coating”, and the construction technical specifications and quality control and acceptance specifications for squeeze coating in the oilfield were formulated to ensure the construction quality. The pipeline used for 1 year was evaluated, and the results showed that the coating surface was complete, the color did not change, and the coating adhesion, hardness and thickness met the design requirement, and the effect was good.