A paper currency detection apparatus, characterized by comprising: a sensor unit for detecting a transmission state of a paper currency according to a fixed clock period, and binarizing the detected signal to represent whether the paper currency appears; a storage unit for collecting the signal detected by the sensor unit, acquiring paper currency information in the signal and storing the paper currency information in sequence; and a control unit comprising a first state counter and a second state counter, wherein: the control unit resets the first state counter and starts the first state counter to count according to the fixed clock period when a time sequence state of the signal detected by the sensor unit represents that the paper currency appears and when a count value of the second state counter is 0 or reaches or exceeds a preset threshod, the control unit adjusts a pointer for recording the paper currency information in the storage unit to point to a next storage location of the paper currency information when a count value of the first state counter reaches or exceeds the preset threshold; the control unit resets the second state counter and starts the second state counter to count according to the fixed clock period when the time sequence state of the signal detected by the sensor unit represents that the paper currency disappears and the count value of the first state counter is 0 or reaches or exceeds the preset threshold; the control unit controls the storage unit to store the acquired paper currency information into the storage location pointed by the pointer when the count value of the second state counter reaches or exceeds the preset threshold. a sensor unit for detecting a transmission state of a paper currency according to a fixed clock period, and binarizing the detected signal to represent whether the paper currency appears; a storage unit for collecting the signal detected by the sensor unit, acquiring paper currency information in the signal and storing the paper currency information in sequence; and a control unit comprising a first state counter and a second state counter, wherein: the control unit resets the first state counter and starts the first state counter to count according to the fixed clock period when a time sequence state of the signal detected by the sensor unit represents that the paper currency appears and when a count value of the second state counter is 0 or reaches or exceeds a preset threshod, the control unit adjusts a pointer for recording the paper currency information in the storage unit to point to a next storage location of the paper currency information when a count value of the first state counter reaches or exceeds the preset threshold; the control unit resets the second state counter and starts the second state counter to count according to the fixed clock period when the time sequence state of the signal detected by the sensor unit represents that the paper currency disappears and the count value of the first state counter is 0 or reaches or exceeds the preset threshold; the control unit controls the storage unit to store the acquired paper currency information into the storage location pointed by the pointer when the count value of the second state counter reaches or exceeds the preset threshold.