Banknote detection device and cash withdrawing method and device

The invention provides a banknote detection device and a cash withdrawing method and device. The banknote detection device comprises a data interface, an induction switch, an infrared laser transmitter and a wavelength detector. The data interface is used for receiving trigger pulses sent by a master control mobile phone; the induction switch is used for starting the infrared laser transmitter and the wavelength detector after inducing that the data interface receives the trigger pulses sent by the master control mobile phone; the infrared laser transmitter is used for transmitting infrared laser and illuminating anti-counterfeit features on a banknote; the wavelength detector is used for detecting the wavelength of the laser produced after the anti-counterfeit features are illuminated by the infrared laser, and the detected wavelength is used for judging the authenticity of the banknote. The banknote detection device and the cash withdrawing method and device solve the technical problem that in the prior art, a banknote detection device depends on the performance of a mobile phone, and accordingly banknote detection accuracy is difficult to guarantee, and the technical effect that the banknote can be accurately detected is achieved.