As a key component of a high-power wheeled tractor, the front axle suspension plays an important role in absorbing the vibration caused by random road excitation, and the plug-in proportional valve provides an important support for the vibration control of the front axle suspension system. For developing the design capability of exclusive agricultural machinery, a hydraulic system circuit of the plug-in proportional valve for the front axle suspension system was developed, and its structure mechanism was analyzed to construct the front axle suspension system that can be opened in time. On the basis of this situation, a nonlinear mathematical model was established to clarify the inherent relationship between design component and suspension performance. And then, various modes of front axle suspension with adjustment damping can be realized via the design optimization of the component parameters. In addition, in order to reduce the uncertainty of the design component parameters and the repeatability of the design schematic, Taguchi design method was introduced to implement and take the accumulator, throttle valve size, proportional valve as design factors. Step and sinusoidal excitation were regarded as noise factor. A 6-factor mixed level Taguchi experimental design schematic was developed. Subsequently, the variance analysis of the signal to noise ratio and mean value of each design scheme were derived. Combined with the AMEsim simulation model, the optimal design scheme was analyzed and verified on the basis of the evaluation indicator with suspension output force and sprung mass vibration acceleration, the sprung mass vibration acceleration can be reduced, which can effectively improve the driving comfort of the tractor. On the basis of the AMEsim simulation model, the dynamic property of the optimal design scheme was analyzed. When the load was changed, the pressure of the two chambers of the hydraulic cylinder can be adjusted to the equilibrium position with about 2s;when the road was excited by step, the plug-in proportional valve can respond quickly, the adjustment time was less than 0.5s, which can promote the ride comfort of the wheeled tractor, thereby enhancing the design capability and providing the reference for the design and development of the front axle suspension system for high-power wheeled tractor.