The invention relates to the technical field of paper money conveying, and provides an automatic transaction device and a paper money conveying device thereof. The paper money conveying device comprises two conveying mechanism which are oppositely arranged in a paper money conveying direction, wherein each conveying mechanism comprises a driving assembly, driven assemblies, and conveying belts. The driving assembly comprises a driving shaft with one end being connected with a power part, and a plurality of driving wheels which are fixedly installed on the driving shaft. Each driven assembly comprises two driven shafts arranged coaxially, a plurality of driven wheels which are respectively installed on the driven shafts in a fixed manner, and a shaft coupler which is connected between two driven shafts. The driven wheels of each driven assembly and the driving wheels of the driving assembly are corresponding and aligned in a one-to-one manner. The conveying belts are used for enabling the driven shafts to rotate when the driving shaft rotates, and are respectively wound on the driving wheels and the driven wheels, corresponding to the driving wheels, of each driven assembly. Compared with the prior art, the paper money conveying device is high in structural stability, and the synchronous belts cannot interfere with each other, thereby avoiding the loss of paper money.