In recent years, the large-scale construction of offshore power transmission projects has frequently resulted in the formation of “common corridors,” where high-voltage AC cables run parallel to nearby underwater pipelines. This arrangement generates alternating current-induced voltage and current in the pipelines, exposing them to AC interference risks. While substantial research has focused on the AC interference patterns of onshore oil and gas pipelines, systematic studies and mechanistic analyses of AC interference risks in underwater pipelines remain limited. To address this gap, this paper establishes a calculation model for AC interference on submarine pipelines caused by high-voltage AC cables using CDGES software. Through simulation calculations, the study investigates the influence of various factors on the pipeline’s AC interference parameters, including the parallel distance between AC cables and pipelines, parallel length, cable voltage level, anticorrosive coating resistivity, load current imbalance, and environmental resistivity. The results indicate that as the parallel length increases, both a maximum AC interference parallel length and a saturation parallel length exist. Utilizing the principles of electromagnetic induction and AC circuits, this paper clarifies the main reasons for these phenomena, along with the variations in pipeline AC interference along the corridor. Furthermore, The safe distances avoiding AC corrosion under different parallellengths and load currents were discussed, which can provide a reference forthe evaluation of AC interference of submarine pipelines and the selection of submarine routing.