Abstract: The Gaussian beam migration method is widely used in seismic imaging due to its high efficiency, flexibility, and good adaptability to anisotropic media. Least-squares migration (LSGBM) based on Gaussian beams theoretically offers superior imaging accuracy, yet it still faces challenges in computational efficiency and stability. To improve the imaging quality of subsurface complex structures, this paper proposed an image-domain non-iterative least-squares Gaussian beam migration method suitable for transversely isotropic (TI) media. First, anisotropic ray tracing was employed to compute the travel time and amplitudes of Gaussian beams, thereby constructing the Green’s functions for TI media. Subsequently, the point spread function (PSF) of the subsurface space was analytically characterized based on the Green’s function, serving as an approximation of the Hessian matrix. Finally, the point spread function was used to perform high-dimensional deconvolution on the classical anisotropic Gaussian beam migration result, achieving image-domain non-iterative least-squares migration imaging in TI media. Validation using synthetic models demonstrates the method’s good imaging performance in TI media, and application to real seismic data further confirms its potential.