Abstract: As the approximate theoretical calculation method of the induced voltage and current for parallel lines commonly used as present fails to consider complete factors in its calculation and often leads to inaccurate results,this paper proposes a new accurate calculation method based on the superposition principle to calculate the induced voltage and current respectively. In addition,an approximate calculation method convenient for engineering application is proposed.These two methods are used to calculate the induced voltage and current of a 330 kV double-circuit line on the same tower. The results show that the approximate calculation method can meet the engineering needs. Further research shows that the influence of the line resistance on the induced current can not be ignored.