The vibration comfort of commercial vehicle is improved in two ways where the data for the road-test are used as excitation and validation signals. The cab structure is optimized in HYPERMESH.At different speeds,acceleration RMS of the driver’s seat is reduced by 6% on average compared with the previous structure in ADAMS. In terms of the cab suspension,a multi-body dynamics model based on flexible cab is built. Taking the acceleration RMS as the evaluation target,the orthogonal test for optimizing the stiffness and damping of the suspension is conducted in the frequency domain. The different dynamic deflections are compared in time domain..At different speeds,acceleration RMS of the driver's seat is reduced by 10% on average after optimization of the cab suspension,dynamic deflection is reduced by 21% on average.