Abstract: With the development of social economy, the corridor resources of transmission lines are becoming tense, so it is very important to improve the utilization efficiency of the corridor. 500 kV and 220 kV lines been erected on the same tower, which can intensively use the corridor path and greatly reduce the demolition cost and construction difficulty. However, when different voltage lines are erected on the same tower, the electromagnetic induction between circuit lines should be calculated to ensure the safety of line equipment and personal. In this paper, according to the tower model and conductor parameters, using ATP-EMTP to build model, analyze the induced voltage and current four circuit lines on the same tower. Final it can provide reference for future project design.