Abstract: Significant anisotropy and tilted symmetry axes are commonly observed in deep complex structural zones. Imaging methods based on isotropic or oversimplified anisotropic assumptions lead to velocity inaccuracies, mispositioned events, and distorted structural features. To address these issues, this paper investigates reverse time migration in 3D tilted orthorhombic (TORT) anisotropic media. First, based on the ORT medium assumption, we derive a 3D TORT wave equation accounting for both the dip and azimuth of the symmetry axis, which enables 3D forward modeling. On this basis, reverse time migration using the 3D TORT wave equation is implemented with the normalized cross-correlation imaging condition. Numerical results demonstrate that the proposed method accurately images the positions and geometries of reflection interfaces under complex 3D structural conditions characterized by strong anisotropy and tilted symmetry axes, making it favorable for imaging in highly anisotropic settings such as fractured hydrocarbon reservoirs.