Banknote detection method and detector with image acquisition and computing device

The present invention provides a banknote detection method and a detector with an image acquisition and computing device. The method comprises the following steps that firstly a banknote sending device is controlled to move to send a banknote, a light source is controlled to emit multispectral illumination in a time-sharing way, the images of the banknote at different spectrums are collected through an imaging device, the obtained image characteristics of the images in step (3) are extracted and are expressed as a mathematical description Y =X(1)*W(1)+X(2)*W(2)+X(3)*W(3)+X(n)*W(n), wherein X represents a counterfeit characteristic and W represents a weight, the obtained Y and a judgment threshold value obtained according to the banknote counterfeit characteristic are compared, if Y does not exceed the threshold value, the steps (1) to (5) are repeated, and if Y exceeds the threshold value, the banknote is judged as a counterfeit banknote and the banknote sending is stopped. According to the banknote detection method and the detector, through employing the same imaging device to realize the double-sided imaging of the banknote, the authenticity of the banknote is identified, thus the volume of the detector or banknote identification device is reduced, and the detector or banknote identification device is easy to carry.