Abstract: This paper introduces the design principle of cathodic protection for buried pipeline. Through detecting the CP potential of Lanzhou-Chengdu-Chongqing analyzing the technical reform results of CP, it is pointed out that the CP design of long-distance pipeline should lay stress on the on-the-spot investigation, the special technique take for CP in some mountainous pipe sections, especially for the pipeline at high soil resistivity, and the near-anode CP technique should be adopted in this soil environment in order to ensure the CP's availability and effectiveness to safely run the pipeline.