High-pressure polarized Raman spectroscopy (HPRS) is a spectroscopic technique that uses a diamond anvil cell (DAC) as a pressure-generating device to systematically control the polarization directions of both incident and scattered light in order to measure the angular dependence of Raman spectral intensities under different pressures. This enables the quantitative extraction of the pressure evolution of Raman tensor elements. In this study, we develop an in situ high-pressure polarized Raman setup based on a backscattering configuration, which includes a half-wave plate that enables continuous variation of the polarization angle without rotating the sample. Quantitative determination of Raman tensor elements is achieved through polar coordinate fitting of the measured intensity profiles. Single-crystal Si (100), commonly used for Raman calibration, and two-dimensional Te (110) flakes exhibiting in-plane anisotropy are selected as model systems for investigation. Our results show that in a pressure range of 0–12 GPa, the angular distribution pattern and periodicity of Si (100) remain unchanged, while the main Raman peak exhibits an approximately linear blue shift as pressure increases. The Raman tensor element related to the active mode decreases according to an inverse power-law function, reflecting the response of the polarizability derivative to volume compression in the absence of phase transition. For two-dimensional Te (110), the in-plane anisotropy increases with the increase of pressure, accompanied by deviations of certain modes from ideal symmetry-predicted behavior. Notably, the ratio of Raman tensor elements exhibits a turning point near 1.5 GPa, transitioning from a decreasing to an increasing trend, with polarized Raman responses clearly changing within a range of 1.2–1.6 GPa range. It is very close to the electronic structure phase transition point determined by transport experiments (about 2 GPa). Overall, studies on single-crystal Si (100) and two-dimensional Te (110) demonstrate that HPRS is a robust in situ method for probing symmetry evolution, anisotropic behavior, and incipient electronic rearrangements in materials under compression.