Polarization metasurfaces are innovative optical devices that can precisely control the polarization state, phase, and amplitude of light by designing micro-nano structures of different materials. Most existing polarizers have limited functionality and larger sizes due to their fixed physical structures and material properties, making it difficult to meet the demands for miniaturization and multifunctionality in modern optical systems. This article investigates a tunable phase-change polarization metasurface based on an all-dielectric GaAs/ Sb2 Se3 structure operating in the near-infrared wavelength range ( 780 ~ 1 100 nm). By integrating polarization conversion meta-atoms and phase-switching meta-atoms, a linear polarization device with high transmittance (99. 625% ), high extinction ratio (32. 8 dB), and controllable polarization angle is designed. Notably, the introduction of the phase-change material Sb2 Se3 enables dynamic tuning of the polarizer under different phase states, offering significant advantages for controlling the polarization state across various wavelength ranges. The effectiveness of the design is evaluated through theoretical analysis and finite - difference time - domain simulations, demonstrating the broad application potential of this metasurface in infrared detection, imaging, and communication. This research provides an innovative solution for the miniaturization and multifunctionality of optical systems and lays the foundation for future material optimization and exploration of new applications.