Abstract: Lightning protection is one of the means for detecting an important part of the mine disaster reduction, and one of the earth resistance measurement is the key and the main content of the lightning protection device testing, also important technical indicators, but also the determination is the entire mine facilities qualified important basis. In routine testing work,due to the different grounding object to be measured using different grounding objective environment, often encountered ground resistance readings unstable and inaccurate phenomenon, if not carefully analyze local conditions, proper calibration,measurement the result will affect the accuracy of measurement affect the impartiality of the data. On this, The writer of this paper conclued testing methods of lightning protection devices through the practice and exploration of several years.