A six-degree-of-freedom model of the aircraft with unidirectional constraint on pavement was established based on the B737-800 aircraft. The simulation calculation of aircraft taxiing were carried out on the pavement with single and stochastic uneven excitation respectively. Results show that, under the single uneven excitation input, the vibration response of the aircraft no longer changes monotonously with the wavelength and amplitude of the pavement deformation and the aircraft taxiing speed but the deformation model of the pavement, which is significantly different from that without considering the unidirectional constraint of pavement. The sensitive band of different taxiing speed is not the same. Under the stochastic uneven excitation input, the time when the wheels disengage from the pavement increases with the deterioration of pavement roughness. When the international roughness index of pavement is 3 m/km and the aircraft taxis at a speed of more than 70 m/s, and the taxing distance of the wheel separated from the pavement accounts for more than 1/4. The main frequency of the aircraft vibration response becomes lower, and the high-frequency vibration is greatly attenuated, and the vibration energy is concentrated to lower frequency. Between the two indexes for evaluating the roughness of pavement, the vertical maximum acceleration of the aircraft’s center of mass increases compared with that without considering the unidirectional constraint, while the root mean square of the vertical acceleration decreases because the downward acceleration response is weakened by the departure of the wheels from the pavement.