Oil and gas pipelines (X52 steel) in the marine environment are highly susceptible to corrosion. The effects of different dissolved oxygen concentration, pH, and hydrostatic pressure on the corrosion behavior of X52 pipeline steel in the marine environment was analyzed using electrochemical testing technology and observation of corrosion morphology. The results show that the corrosion of the pipeline slowed down as the ambient pH increased, while the corrosion of the pipeline steel increased as the dissolved oxygen content and hydrostatic pressure increased. The corrosion behavior of pipeline steel under different conditions is controlled by anodic activation of dissolution, and all appear local pitting corrosion phenomenon.