The invention discloses a multi-path reversing device of a lorry-mounted crane. The multi-path reversing device comprises an oil inlet oil path, an oil return port, an amplitude changing
reversing valve used for operating three actions including ascending, stopping and descending of an amplitude changing oil cylinder, a telescopic
reversing valve used for operating three actions including stretching out, stopping and contracting back of a telescopic oil cylinder, a
winch reversing valve used for operating three actions including ascending, stopping and descending of a
winch motor, and a rotation reversing valve used for operating three actions including the forward action, stopping and the reverse action of a rotation motor, and a
functional module. The amplitude changing reversing valve and the telescopic reversing valve are connected with the two ends of the oil inlet oil path in parallel, the rotation reversing valve, the
functional module and the oil inlet oil path are connected in series, and after being gathered, the telescopic reversing valve and the
functional module are sequentially connected with the
winch reversing valve and the oil return port in series. According to the device, five composite actions including amplitude changing and winching, amplitude changing and rotation, telescoping and winching, telescoping and rotation and rotation and winching are achieved, composite actions can be achieved without a proportional multi-path valve, cost is effectively reduced, and the
cost performance of straight arm lorry-mounted cranes is improved.