<p>The herringbone gear with symmetrical error will lead to the increase of eccentric load in the transmission process. According to the lumped mass method, the bending-torsion-axis coupling dynamic model of herringbone gear-bearing transmission system considering symmetrical error is established. The influence of different symmetry errors on the vibration characteristics of herringbone gears is analyzed. The results show that the symmetry error will gradually increase the difference between the dynamic load coefficients of the left and right meshing pairs. Compared with the radial displacement, the axial vibration displacement changes greatly with the increase of error. A herringbone gear-bearing transmission test bench was built to verify the correctness of the theoretical model.</p>