The invention introduces a passive thunder and lightning detector, including a monitoring meter body and a first coil which are fixedly connected. The first coil sleeves a discharging conductor of a detection tower; a cylindrical iron core is fixed between two poles of a hoof-shaped magnet inside the monitoring meter body; the cylindrical iron core is externally sleeved by a rotatable aluminium frame, a second coil is wound on the aluminium frame; two wire tails of the second coil are connected with two wire tails of the first coil; two ends of the aluminium frame are each provided with a rotating shaft; the rotating shaft can rotate bidirectionally along the aluminium frame; the tail of a pointer are installed on the rotating shaft of the front end of the aluminium frame; and one of the rotating shafts is equipped with a first gear capable of follow the rotating shaft to rotate bidirectionally, and left and right sides of the first gear are provided with a second gear and a third gear respectively which are meshed with the first gear in a transmission manner and can only rotate unidirectionally. The passive thunder and lightning detector has the advantages of: 1) being capable of substantially reducing the workload of operation personnel of an overhead transmission line; 2) being capable of substantially reducing dangerousness of climbing a pole to check the line during a lightning storm; and 3) being capable of realizing accurate positioning of a fault tower.