The invention discloses an automatic identification method for damages of an RFID (Radio Frequency Identification) ground tag. According to the invention, a first locomotive runs on the railway line,when an RFID tag reader installed at the bottom of the locomotive reads location information of an Nth tag on the ground, a vehicle-mounted system compares the read location information of the Nth tagwith location information of the Nth tag in a tag physical location information base, and the vehicle-mounted system judges that the Nth tag is not read by the first locomotive or the Nth tag breaksdown if the read location information of the Nth tag cannot be matched with the location information of the Nth tag in the tag physical location information base; judgment is performed on a reading result of the Nth tag according to a second locomotive; the second locomotive runs on the railway line, when the RFID tag reader reads the location information of the Nth tag, the vehicle-mounted systemcompares the read location information of the Nth tag with the location information of the Nth tag in the tag physical location information base, and the vehicle-mounted system judges that the Nth tag is missed by the first locomotive if the read location information of the Nth tag is consistent with the location information of the Nth tag in the tag physical location information base; and if theread location information of the Nth tag cannot be matched with the location information of the Nth tag in the tag physical location information base, the vehicle-mounted system judges the Nth tag breaks down.