The invention provides a hill and mountain tractor body attitude adjusting device and an adjusting method. Axle adjusting components of the hill and mountain tractor body attitude adjusting device are symmetrically mounted at the bottom of a body; the hill and mountain tractor body attitude adjusting device comprises axles, attitude adjusting hydraulic cylinders, stabilizers and variable connecting rod groups; the attitude adjusting hydraulic cylinders and the variable connecting rod groups are both symmetrically hinged between the body and the axles; each variable connecting rod group comprises two connecting rods, which are hinged between the body and the axles and parallel to each other in an up-and-down direction; the stabilizers are mounted between the body and the axles; an electronically controlled hydraulic system comprises a sensor, a signal collection unit, an attitude controller and an electronically controlled hydraulic valve which are connected with each other via signals; and the electronically controlled hydraulic valve controls the attitude adjusting hydraulic cylinders. According to the adjusting method, vehicle attitude information detected by the sensor is transmitted to the attitude controller by using the information collection unit, and then the electronically controlled hydraulic valve is controlled to adjust the attitude adjusting hydraulic cylinders, and finally, self-adjusting of body attitude is realized. According to the hill and mountain tractor body attitude adjusting device and the adjusting method, the body attitudes of wheeled vehicles are self-adjusted in real time to guarantee the running stability.