Articulated engineering vehicle travels on complex road, its working condition is bad and because of the non-rigid connection between the front and rear body, additional degrees of freedom is brought in and the transverse stiffness is relatively weak. When the articulated vehicle run in a high speed along a straight line, it is easy to cause the transverse swing and the poor manipulation stability. If it is serious enough, it will lead to "snake shape" instability phenomena. This kind of instability will increase driving resistance and tire wear, the lateral dynamic load and aggravate the damage of the parts. When steering, the center of gravity will offset laterally which will lead a higher probability of rollover accident. A mathematical model for a 35t articulated dump truck with four motor-driven wheels is established in this paper, to study the condition for its stable driving and the effects of the vehicle structural parameters. This part research focus on the position changes of the pivot and front and rear axle center which impact the manipulation stability. Then an ADAMS simulation model is built and simulation of steady state circular test and steering wheel angle step input test are conducted to observe the manipulation stability of vehicle and compare the results in unload, full load and different steering angle step inputting. On this basis, further study on the effects of the mass center position of rear body on vehicle maniputation stability. The results of simulation has a good reference value for the vehicle manipulation stability design and verify the correctness of the models.