The invention relates to a grounding simulation test positioning system and a positioning method thereof. The system comprises guide rails on two sides of an analog tank as well as a travelling crane, a movement control system, a measurement system, a monitoring system and a controller, which are connected to the parallel guide rails; the system can transmit a move command to the movement control system through the controller and the monitoring system and can move a probe to an assigned position; the measurement system feeds two-dimensional coordinates of the probe back to the controller. The system and the method provided by the invention relieve operation intensity of experiment personnel, avoid man-made reading errors, and improve measurement reliability and safety.