The invention discloses a grounding fault transient current generator, which comprises a grounding transformer, wherein the grounding transformer is connected with a system bus, a neutral point is led out of the grounding transformer to be connected with a monostable switch, the monostable switch is connected with the ground, the grounding transformer and the monostable switch are both fixed to a mounting bottom plate, four corners of the mounting bottom plate are in threaded connection with inserting rods, the outer rings, which are located on two sides of the mounting bottom plate, of the inserting rods are in threaded connection with locking nuts, the lower ends of the inserting rods are fixedly connected with deeply-buried blocks, the upper ends of the deeply-buried blocks are fixedly connected with lower sleeve plates, and outer rings of the inserting rods sleeve upper sleeve plates. According to the invention, the neutral point led out of the grounding transformer is connected with the monostable switch, when a system branch breaks down, the monostable switch is triggered, the reliability and safety of system power supply are improved, the manufacturing cost is low, and installation and operation are convenient. In addition, the deeply-buried blocks connected with the lower ends of the inserting rods and the lower sleeve plates and the upper sleeve plates which are connected with the inserting rods are deeply buried into the ground, so that the overall stability and the inclination resistance are improved.