A 7-DOF vehicle model is proposed based on Matlab/Simulink. The longitudinal and lateral tire forces are computed by Dugoff tire model. The proposed model provides a relatively comprehensive mathematical characterization for tire blow-out course and can simulate vehicle dynamics after tire blow-out in different driving conditions. Taking the curve driving situation as an example, the vehicle responses before and after tire blow-out are compared for a heavy-duty truck in detail. It is found that after tire blow-out the heavy-duty vehicle will run at a bigger turning radius and a higher speed and the longitudinal force of the blow-out tire will rise greatly, but the lateral and vertical tire forces will reduce. Eventually the vehicle will run away from the route and lose handling stability.