A system for automatically attaching a radio frequency identification (RFID) tag label and a method thereof are provided. The system includes: an RFID printer for writing original tag information of an object to an RFID tag attached to one surface of the RFID tag label, printing a bar code on the other surface, and outputting the RFID tag label; an applicator for fixing in place the RFID tag label output by the RFID printer and attaching the RFID tag label to the object by applying predetermined pressure; a verification RFID reader including an antenna located near the applicator for reading the written original tag information to verify whether the tag information is correctly recognized from the RFID tag label attached to the object; a warning device for warning a user when the tag information is not correctly recognized from the RFID tag label attached to the object; and a control device for performing control to deliver the original tag information of the object from the exterior to the RFID printer, receiving the read tag information from the verification RFID reader, comparing the read tag information with the original tag information of the object to determine whether the read tag information is consistent with the original tag information, and controlling operation of the warning device based on the determination result, thereby preventing, in advance, errors such as erroneous information for an object distributing process from being generated due to recognition failure, errors and the like.