The inflatable wing with inflated pressure has a large deflection which leads to a deviation compared with target shape. Such deviation has a great influence on the aerodynamic shape of the inflatable wing, which decreases the precision of structural analysis. In this paper, we proposed a novel inverse iterative method to obtain the accurate 3D initial shape of the unpressured inflatable wing. The initial shape of the Lattice Inflatable Wing is then obtained accurately by combining the inverse iterative method and the APDL program. The non-contact tests are performed to validate the inverse iterative method in the end. The results reveal that the proposed inverse iterative method is an accurate and effective method which may be used to obtain the 3D initial shape of inflatable wing with zero pressure. This method has high computation efficiency, good convergence and reliable characteristic.