Abstract: During the construction process, it is often difficult to maintain an ideal state of the shield tunnel excavation axis, and the cutterhead may deviate in various directions along the tunnel circumference, resulting in the misalignment between the cutterhead center and the segment center, making the existing load calculation methods for shield tunnels inadequate. In view of this, an analytical model for soil deformation due to shield attitude deviation is established, and a method for calculating the additional loads resulting from such deviations is proposed. Based on the existing stress function forms and combined with certain boundary conditions, a formula for calculating the additional earth pressure due to shield attitude deviation is derived. Finally, the rationality of the additional earth pressure formula is verified through numerical calculations and in-situ tests, and sensitivity analysis is conducted on the main influencing parameters. The results show that the theoretical and numerical calculations show significant discrepancies at the crown and invert, but the two exhibit a good overall agreement. The Terzaghi formula ignores the influence of shield attitude offset on the earth pressure of the tunnel, which leads to a large difference between the calculated earth pressure and the actual earth pressure of the tunnel. And the value of the modified formula is more consistent with the value of in-situ tests. And the deviation-induced additional earth pressure in soft ground gradually becomes less sensitive to changes in tunnel burial depth. Conversely, it is more sensitive to the change of deviation, soil elastic modulus, internal friction angle and cohesive.