The invention provides a paper currency transmission structure used in a paper currency sorting machine. The paper currency transmission structure comprises a driving roller wheel, a paper currency conveying device and a paper currency pulling structure, wherein the paper currency pulling structure comprises a mounting piece and a first paper currency pulling roller wheel pivoted on the mounting piece; the paper currency conveying device comprises a guide plate, a bottom plate, a mounting part fixedly arranged on the guide plate and a paper currency conveying structure rotatably connected to the guide plate; a paper currency conveying passage is arranged between the guide plate and the bottom plate; the paper currency conveying structure comprises a first paper currency conveying roller wheel; the mounting piece is pivoted on the mounting part; the first paper currency pulling roller wheel and the first paper currency conveying roller wheel trigger the driving roller wheel; the driving roller wheel is used for driving the first paper currency pulling roller wheel and the first paper currency conveying roller wheel to rotate, so that paper currencies are driven by the first paper currency pulling roller wheel and the first paper currency conveying roller wheel so as to enter into the paper currency conveying passage.