Abstract: Objective The aim was to solve problems such as poor fluidity of molten metal, uneven and discontinuous back weld and unstable welding quality in all-position welding of microbial corrosion resistant pipe that was rich in Cu and Cr elements. Methods Taking corrosion resistant pipe BGL450Q-RCB as the test object, research on oscillating arc backing welding process based on back forced forming of copper backing was carried out. Single factor analysis method was used to study influence of oscillating arc parameter, wire feed speed, and welding speed on quality of weld forming. Results The results showed that oscillating arc backing welding method with back forced forming of copper backing had good consistency of weld forming, and back of weld was formed continuously and flat, without defects of incomplete fusion and incomplete penetration. Conclusion The study lay foundation for the development of basic process specification for all-position welding of pipelines.