Under the condition of alternating current (AC) interference, the current domestic and international standards impose restrictions on the cathodic protection off-potential. According to the provisions of GB/T 40377–2021 and SY/T 0087.6–2021, when the AC current density is less than 100 A/m², the polarization potential is required to be between −0.9 and −1.15 V_CSE. However, to reduce the dynamic direct current (DC) interference corrosion risk of the metro, the cathodic protection potential of pipelines in the Pearl River Delta region is mostly lower than −1.15 V_CSE. Therefore, to accurately assess the AC corrosion risk of buried pipelines in the Pearl River Delta region, this study focused on the typical soil environments encountered by pipelines in this area. Laboratory simulation experiments were conducted to establish the correlation between pipeline AC/DC parameters and corrosion behavior, aiming to propose AC interference assessment criteria and methods suitable for the typical environments of the Pearl River Delta. The results show that when the AC current density is less than or equal to 100 A/m², the corrosion rate is less than 0.03 mm/a under three cathodic protection potentials of −0.9, −1.15, and −1.2 V_CSE. With the negative shift of the polarization potential, the AC corrosion rate increases. When the AC current density is greater than or equal to 200 A/m², the corrosion rate of the samples is higher than 0.03 mm/a under all three cathodic protection potentials. According to the experimental results, the AC corrosion evaluation index for the typical environment of the Pearl River Delta, where the AC corrosion rate is less than 0.03 mm/a is as follows: when the AC current density is less than or equal to 100 A/m², the range of the polarization potential is −0.9 to −1.2 V_CSE. When the AC density reaches 500 A/m², the corrosion rate of the specimens increases with the negative shift of the cathodic protection potential, which originates from the dynamic evolution mechanism of the corrosion product film under the combined action of high AC interference and increasingly negative cathodic protection potentials. During the positive half-cycle of the AC signal, a complete oxide film layer forms on the specimen surface. In the cathodic reaction stage, the hydrogen evolution reaction generates hydrogen bubbles, causing the oxide film layer to become porous and loosely structured. The specimen surface undergoes a cyclic process of formation, rupture, and loosening of the Fe₃O₄ product film layer, ultimately leading to a notable increase in the corrosion rate of the specimen.