Oil and gas transportation pipeline is the energy artery of social development and it is of momentous significance to ensure the pipeline operates safely.Based on the measured data of HVDC grounding electrode discharge, this paper systematically identifies the hazard brought by HVDC grounding electrode discharge to oil and gas transportation pipeline.The two main factors that affect the hazard include the degree of electrical interference suffered by pipelines and the tolerance of pipeline system. The hazard can be summarized as pipe damage, corrosion protection layer stripping, drain ablation and excessive consumption of grounding materials, valve chamber process equipment ablation, lightning protection ablation, insulation joint breakdown and inner wall corrosion, cathodic protection equipment ablation, transformer dc magnetic bias and electric shock.It is suggested to adopt equipment and facilities with good tolerance, and control the interference intensity of HVDC grounding electrode discharge from the source,evaluate the risk caused by HVDC grounding and take protective measures corresponding to the interference degree to ensure the pipeline operate safely.