The invention provides an invoice folding device, an invoice folding system and an invoice self-service terminal. The invoice folding device comprises a connection shaft, a rotating body, a first stoprod and at least one first bevel gear. The rotating body is rotationally arranged on the connection shaft in a sleeving manner. The first stop rod is connected to the outer wall of the rotating bodyin the radial direction. Each first bevel gear is rotationally arranged on the connection shaft in a sleeving manner. At least one end of the rotating body is connected with the corresponding first bevel gear. According to the invoice folding device, each first bevel gear and the corresponding end of the rotating body are connected, in this way, rotation of the first bevel gears can drive the rotating body to rotate, so that the first stop rod connected with the rotating body can be driven to rotate, rotation of the first stop rod achieves the guiding function on continuous invoices, then thecontinuous invoices can be folded according to the crease, and therefore automatic folding of the invoices is achieved. Besides, the invoice folding device is simple in structure and easy to implement.