Test system for grounding grid

The embodiment discloses a test system for a grounding grid. The test system comprises piles, a power supply forming a set frequency difference with power frequency, human body simulation resistors, a parameter acquisition device and an arithmetic device. The piles comprise current piles and voltage piles. The parameter acquisition device is used for acquiring current values of the current piles and voltage values of the voltage piles, acquiring a distance between a first pile and a second pile and a distance and a resistance value between the second pile and a third pile, and acquiring voltage values at the two ends of each of a first human body simulation resistor and a second human body simulation resistor, wherein the current values of the current piles and the voltage values of the voltage piles are measured according to a straight-line method; and the distance between the first and second piles and the distance and the resistance value between the second and third piles are measured according to a quadrupole equal-interval method. The arithmetic device is used for calculating grounding resistance, soil resistivity, contact resistance and step resistance according to a set formula. Non-power frequency current is used for testing, so that the interference of the power frequency to the measurement current is avoided, the adoption of heavy current for measurement is not required, and the size of the measurement power supply is reduced.