The invention relates to a gear sensing device and a using method of the gear sensing device. The gear sensing device comprises a circuit board, a plurality of inductors are arranged on the circuit board, a metal plate is arranged above the inductors, a plurality of through holes are formed in the metal plate, the metal plate can move relative to the circuit board, the number of gears is set to beN, N is larger than or equal to 2, the number of the inductors is at least M, and 2<M-2><2<=2<M-1>, the number of the through holes is at least 2N-M, the metal plate is controlled to move relative tothe circuit board to enable the inductors to be exposed out of the through holes so as to obtain different binary codes, the inductors are arranged in sequence, the codes are set to be 0 when the inductors are exposed out of the through holes, the codes are set to be 1 when the inductors are shielded by the metal plate, and different binary codes are obtained when the metal plate is moved to different gears. By adopting the technical scheme, according to the gear sensing device and the using method of the gear sensing device, the structure is simple, precision is high, the redundant capacityis high, gears can still be recognized after some inductance signals lose efficacy, and stability is high.