The Tongxiang pipeline of the Xiangguosi gas storage project suffered DC interference of the subway stray current which was unpredictable at the design stage, and the interference extent and range could be known through actual measurement only after the pipeline was put into operation, resulting the Tongxiang pipeline pipe-to-soil potential fluctuated intensely.Normal cathodic protection could not be provided for pipeline，and the original cathodic protection system failed to operate properly.After on-site testing and data analysis, through the study of the characteristics and patterns of urban track interference and the applicability of various drainage methods to Tongxiang pipeline, combined with the actual situation of the project, the methods for protection of cathodic protection stations under DC interference was proposed for normal operation.After commissioning, the data recorder UDL2 was used to gather pipeline potential data for a long period of time，and field test verification was carried out as well, with the dynamic potential evaluation method proposed by Australian Standard AS 2832.1 to evaluate the effect of drainage protection.According to the evaluation results, the interference suppression effect is obvious, and the cathodic protection system of Tongxiang pipeline can operate normally.