Discussed the relationship of the parameters as magnetic core, induction coil and load based on the theory of electromagnetism. Deduced the basic formula of energy supply device in order to acquire the maximal energy from the transmission line for the robot. 从电磁场基本理论出发,本文讨论了铁芯、感应线圈、负载等参数与输出功率之间的关系,为巡线机器人能最大限度地从输电线路中取得能量得出了匹配公式;