Four-advancing and two-retracting engineering machine gearbox

The invention belongs to the technical field of engineering machine speed changing equipment, and provides a four-advancing and two-retracting engineering machine gearbox. The four-advancing and two-retracting engineering machine gearbox comprises a box body, the box body is internally provided with a power input shaft and a power output shaft, the box body is further internally provided with a first clutch shaft, a second clutch shaft and a third clutch shaft which achieve cooperation with the power input shaft and the power output shaft and transmit power, the power input shaft is connectedwith the second clutch shaft and the third clutch shaft through an input transmission mechanism, the first clutch shaft, the second clutch shaft and the third clutch shaft are connected through a transmission clutch mechanism, and the second clutch shaft and the third clutch shaft are connected to the power output shaft through an output transmission mechanism. By means of the four-advancing and two-retracting engineering machine gearbox, power output of four forward gear positions and two reverse gear positions can be achieved, operation and control are convenient while the work efficiency isimproved, the structure is simple, maintenance is convenient, and the use performance is remarkably improved.