A numerical method is presented to calculate the current and potential of impressed current cathodic protection system for the buried steel pipeline protected by two cathodic protection stations jointly. A resistance circuit with DC supplies is usd to simulate the system through the discretization scheme. Impressed potential and current along the pipeline are found out by mesh-current method. The numerical results have a good agreement with the analytic results and measured ones from Tianjin to Beijing aviation kerosene pipeline. The numerical results show that the coating damage causes increase in protective current and decrease in absolute value of potential along pipeline. The coating damage has less effect on the position where absolute value of potential is minimal, while the output voltage of DC supplies has more on the position. The nearer the location of coating damage is to a cathodic protection station, the bigger the difference of protective currents of the two stations is.