The invention discloses an impulse grounding resistance measuring instrument, which comprises a grounding measurement monitoring system platform and measuring terminals. The grounding measurement monitoring system platform is formed by a three-dimensional real-scene geographical information system, a data storage system, a real-scene geographical information system and a data processing system. Wireless ad-hoc network data messages sent by the measuring terminals are collected and forwarded to an office side center server. A wireless hub is internally equipped with a multi-channel data message-to-Ethernet conversion module and forwards multiple data messages to an internal office network. Each measuring terminal is arranged to a grounding line of each base tower in a key lightning area, is designed like that current transformers are directly lapped to tower foot grounding lines, and is used for collecting data in real time and sending the data to another measuring terminal; and the another measuring terminal receives the data and broadcasts the data to the other measuring terminals in the communication range, and through step-by-step transmission above, finally, the wireless hub arranged in a substation is fed back to the office side center server.