The invention discloses a novel grounding bar burial depth detector which comprises a metal screw rod driven by a motor. The bottom of the metal screw rod is connected with a crescent detection head, and the concave surface of the crescent detection head faces downwards. The metal screw rod is provided with scale lines for indicating detection depth. The motor is connected with a first power supply and a relay to form a motor operating circuit. The metal screw rod is connected with the relay. The relay is connected with the negative electrode of a second power supply. The positive electrode of the second power supply is connected with an alarm. The alarm is connected with a grounding down lead of a grounding bar. When the crescent detection head makes contact with the grounding bar, the crescent detection head, the metal screw rod, the relay, the second power supply, the alarm, the grounding down lead and the grounding bar form an alarm loop. The novel grounding bar burial depth detector is reasonable in structure, light and convenient and visual to use; in the process of testing the burial depth of the grounding bar, the detector can be driven into the ground more rapidly to read the depth value, and therefore testing accuracy and work efficiency are improved.