The tilt-rotor synchronous transmission shaft is crucial in tilt-rotor aircraft, connecting the engine and rotor. The shaft on the flexible wing endures foundation motion and random loads during flight, and different loads impact it variably. This paper models the shaft dynamically, accounting for foundation excitation’s effect on vibration response and analyzing stress and deformation under random loads in helicopter mode. Results indicate that foundation excitation only impacts the action direction, not other directions’ responses. In helicopter mode’s random vibration, the maximum equivalent stress is found on the pinion output shaft.