Based on the three-degree-of-freedom aircraft model, a new airport pavement roughness evaluation theory is proposed. Taking three lines with different roughness grades as input, the three-degree-of-freedom vibration equation of the aircraft model is solved using Matlab/Simulink, through which the three vibration responses are obtained, namely, pitching angle φ, transverse roll angle θ and vertical displacement at the center of mass. By utilizing three vibration response parameters, the distribution of full aircraft roughness index (FARI) along pavement longitudinal direction is acquired. Simultaneously, the international roughness index（IRI）parameter along the same line is calculated. Then the relevance between FARI and the aircraft root mean square value of weighted acceleration, and the relevance between IRI and the aircraft root mean square value of weighted acceleration are analyzed, respectively. The corresponding correlation coefficients are 0.980 6 and 0.886 9.The results show that FARI is a more objective parameter to describe the aircraft bumpy effect in the taxiing process because of pavement fluctuation in the range of all aircraft wheel covering. Therefore, FARI is more suitable for airport pavement roughness evaluation.