The invention discloses a method, a device and a system for bill identification. The method comprises steps that an image of a bill is acquired; the acquired image of the bill is compared with a standard pre-stored bill image, and a comparison result is generated; a to-be-re-check area of the bill is determined according to the comparison result; an amplified image of the to-be-re-check area of the bill is acquired. Through the method, a problem of low identification efficiency of a bill identification method in the prior art is solved, and properties of simple and convenient operation and high identification efficiency are realized.