A paper-type detection device comprises a sensor unit, a storage unit and a control unit. The sensor unit is used for detecting a transmission state of a paper according to a fixed clock period, and carrying out binaryzation on detected signals to indicate the presence-absence state of the paper. The storage unit is used for acquiring the signals detected by the sensor unit, acquiring paper information in the signals, and storing the paper information in sequence. The control unit comprises a first state counter and a second state counter. The control unit controls the two state counters for carrying out zero clearing and starting operations for counting in conjunction with the sensor unit.