The utility model relates to a high voltage cable shielding net grounding wire leakage current detector. The detector comprises an aluminum alloy shell. An alternating current/direct current power supply device and detection apparatus are arranged in the aluminum alloy shell. An anode and a cathode of the alternating current/direct current power supply device are connected with a frequency selection circuit respectively. A secondary side of a current sensor is connected with an I/V conversion circuit through a shielding wire. The I/V conversion circuit is connected with a bidirectional analog quantity output port and the frequency selection circuit respectively. The frequency selection circuit is connected with a filter circuit and a rectification loop respectively. The filter circuit is connected with the rectification loop. The rectification loop is connected with a peak value response time selection circuit. The peak value response time selection circuit is connected with input terminals of a peak value maintenance loop and a LCD driving loop respectively. An output terminal of the peak value maintenance loop 318 is successively and electrically connected with a partial pressure loop, the LCD driving loop and a LCD display screen. By using the detector of the utility model, a problem of cable burning losses caused by multi-point grounding of the existing cable shielding net grounding wire can be timely discovered and solved.