Sliding door is an important part of commercial vehicle. Aiming at the problem of damage caused by the resonance of chuck and wheel in sliding guideway. The three-dimensional force and smoothness of sliding mechanism are studied. An improved guide rail system is designed in the grey model. In the non-linear optimization design [1], the trust domain multi-objective optimization algorithm is used to divide the model into a series of sub-regions. The model is solved iteratively in the trust region of the sub-region, and the design parameters satisfying the requirements of the smoothness of the guide rail are obtained. In ADAMS, the oblique vibration and force motion of components are simulated and analyzed when the track system is running normally. The results show that the force acting on each group of guide wheel mechanism can be effectively decomposed by using the multi-wheel design with separated forces. The smoothness and reliability of the system are improved.