The utility model relates to the technical field of inspection equipment and particularly relates to a counting device which inspects the fin number of a finned tube of equipment of a heat exchanger, an air cooler or the like. The invention discloses a finned tube fin counting device which comprises a guide rail, a sliding trolley arranged on the guide rail, and a counter. The counter is arranged on the sliding trolley. The outer side of the side bottom end of the sliding trolley is provided with a spring piece. One end of the spring piece is connected with the input end of the counter, and the other end of the spring piece is a free end and is in contact with fins. When the finned tube fin counting device is used, the rail can be conveniently installed on a finned tube, with the movement of the sliding trolley on the guide rail, the spring piece vibrates when passes each fin, the vibration of the spring piece drives the counting of the counter, and thus the fins with unit length are accurately counted. The finned tube fin counting device has the advantages of simple structure and convenient use, and through the employment of the device, a problem of inaccurate manual counting of the fins of the finned tube is overcome.