Abstract: In the process of direct current exploration in plain area, when there are grounding metal pipes and lines near the power supply and measuring electrode, the electric field is no longer the electric field of point current source, and the collected data is easy to produce false anomalies. Based on the theory of basic electrical method and the analysis of symmetrical quadrupole device and joint section method, this paper analyzes the causes of interference, summarizes the characteristics of common interference and puts forward some methods to avoid interference, in order to provide reference and reference for similar work.