van der Waals (vdWs) heterostructures provide a superior platform to combine different low-dimensional materials together to tune their physical properties for different types of applications. Specifically, anisotropic heterostructures possess polarization-sensitive optical and electronic properties, which are highly needed in novel optoelectronic devices. However, the achieved degree of polarization (DOP) for the previously investigated heterostructure is relatively low and the induced polarization mechanism and key factors determining the DOP are still unclear. Here, we successfully fabricated an anisotropic TMDC/NbOCl