The invention discloses a heavy off-road vehicle, and belongs to the technical field of vehicles. The heavy off-road vehicle comprises a frame and a cab assembly, a power system, a driving system, a walking system, a steering system and braking systems which are installed on the frame. The heavy off-road vehicle is characterized in that the high maneuverability and the high bearing property are achieved; the frame comprises a main frame body and an auxiliary frame body, the main frame body is of a framework-type rivet connection structure composed of longitudinal beam plates and transverse beam plates, the total width of the structure is the same as that of the main frame body, and the auxiliary frame body is installed on the main frame body and connected with a main frame body support through a connecting base; the power system comprises a six-cylinder in-line water cooling turbine supercharged engine; the driving system comprises an AMT speed changing box connected with the engine, the speed changing box is connected with a power divider through a driving shaft, the power divider is connected with a front axle and a middle axle through the driving shaft, the middle axle is connected with the rear axle through the driving shaft, and walking tires are installed at the two ends of the front axle, the two ends of the middle axle and the two ends of the rear axle respectively; the three independent braking systems including the driving braking system, the parking braking system and the engine exhaust braking system are adopted.