The invention discloses a multifunction vehicle bus interface device which comprises a case, a back plate, a control drive circuit, an interface circuit and two data interfaces connected with the interface circuit. The control drive circuit is arranged on a control circuit board, the control circuit board is inserted in a control slot of the back plate, the interface circuit is arranged on the back plate and is connected with the control drive circuit through a wire arranged on the back plate, the distance between the interface circuit and the control drive circuit is smaller than a distance threshold, the two data interfaces and the interface circuit are arranged on the back plate in a back-to-back mode, and both the two data interfaces are located on the outside of the case. The interface circuit and the two data interfaces are arranged on the back plate on the outside of the case in the back-to-back mode, the interface circuit is electrically connected with the data interfaces through wires printed on the back plate, connecting wire harnesses are saved, fixation of the data interfaces is strengthened, and electromagnetic compatibility is achieved; the interface circuit is directly arranged on the back plate, one slot in the back plate is omitted, and extension of functions of the back plate is facilitated.