In order to determine which panels in cab influent the driver's ear noise greatly, a finite element model of heavy-duty truck cab is established at first, and its accuracy is verified by comparing the computational modal and the experimental modal; On the basis of acoustic-solid coupling model of the cab, the coupling effect of the sound and the structure is obtained when the method of coupling modal analysis is used; Then the driver's ear noise is predicted based on the coupled finite element method, in which the external excitation inputs, the acceleration signals of four cab suspensions, of the acoustic-solid coupling model are sampled from a real vehicle driving test. The comparison of the test value and predictive value further verified the accuracy of the acoustic-solid coupling model; Finally, the panel contribution and the modal participation factor analysis are implemented, by which the panels that have the largest contribution to the peak pressure of the driver's ear noise are identified. At the meaning time, the validity of this conclusions are verified by a comparison of the different driver's ear noise pressures, which sampled from the before and after optimization of the panels thickness.