Polaritons are hybrid quasiparticles formed by the strong coupling between optical fields and material excitations. Research on polaritons has not only deepened our understanding of light-matter interaction mechanisms but also provided new avenues for manipulating nanoscale energy flow. In recent years, a series of polaritons exhibiting exotic propagation characteristics—such as unidirectional, diffraction-free, and ray-like propagation—have been observed in highly anisotropic materials. This review highlights fundamental optical phenomena redefined by anisotropic polaritons at the nanoscale, particularly the anomalous behaviors observed during refraction, reflection, and focusing that defy conventional optical laws. These phenomena hold promise for achieving precise control over light-matter interactions at the nanoscale in broad spectral regions spanning from the visible to the terahertz. At the same time, the methods for manipulating anisotropic polaritons are reviewed; furthermore, based on the latest research progress in the field, the key challenges facing their transition to practical applications and their future development directions are discussed.