Abstract: The anisotropy of subsurface media significantly affects seismic wave propagation, and ignoring this characteristic in reverse time migration (RTM) degrades imaging accuracy. The reliance of the elliptic decomposition method on the asymptotic approximation of wavefield gradients for propagation direction calculations in conventional pure qP-wave RTM for tilted transversely isotropic (TTI) media leads to strong anisotropy, which induces amplitude imbalance and numerical instability. Therefore, this study introduced an optical flow method for the estimation of the wavefield propagation directions of pure qP-waves in TTI media and derived an iterative format for propagation direction vectors adapted to regular-grid finite-difference solutions. Based on the accurate qP-wave dispersion relation proposed by Li, this study derived a pure qP-wave equation for vertical transversely isotropic (VTI) media using the elliptic decomposition method and extended it to obtain the TTI media wave equation via the wavenumber rotation method. By replacing the conventional asymptotic approximation of wavefield gradients with the optical flow method, high-precision and high-stability extraction of the wavefield propagation directions was achieved. Numerical experiments on the strongly anisotropic depression and Hess models demonstrated that the proposed method effectively suppressed the amplitude imbalance caused by asymptotic approximation and achieved an imaging accuracy comparable to that of the pseudo-spectral method with significantly improved computational efficiency. Thus, this method has promising application prospects.