Photodetectors, as multifunctional devices and critical components of photoelectric detection technology, play a pivotal role in converting optical signals into electrical signals within photoelectric systems. Their applications span diverse fields, including infrared detection and night-vision equipment in defense technology, visible-light detection in consumer cameras, and optical communication satellites, demonstrating significant practical value and broad prospects. However, the growing demand for miniaturized, broadband, and polarization-sensitive photodetectors poses new challenges, particularly in developing multifunctional devices capable of room-temperature operation, wide-spectrum response, and polarized-light detection. Sb₂Te₃, an emerging topological insulator material, offers novel opportunities to address these challenges due to its unique optical and electronic properties. Meanwhile, ReS₂ exhibits anisotropic optoelectronic behavior and a stable bandgap, making it promising for polarization-sensitive photodetection. By leveraging these two materials, a multifunctional photodetector was developed, exhibiting room-temperature operation, broadband response, and polarization-sensitive characteristics.The heterojunction device was fabricated through a dry transfer process, comprising three key steps: mechanical exfoliation, material transfer, and metal electrode preparation. The Sb₂Te₃/ReS₂ heterostructure-based optoelectronic device was obtained. Raman spectroscopy, Atomic Force Microscopy (AFM), a low-temperature probe station, a semiconductor analyzer, and lasers with various single wavelengths were utilized to characterize the microscopic morphology and optoelectronic properties of the device.AFM and Raman spectroscopy confirmed the formation of a high-quality heterointerface, with ReS₂ and Sb₂Te₃ layer thicknesses of 20 nm and 50 nm, respectively. Transfer curves tests of individual materials revealed P-type (Sb₂Te₃) and N-type (ReS₂) behavior, indicating efficient charge separation at the heterojunction. The device exhibited a c broad spectral response from 400 nm to 1550 nm with low dark current. Under 532 nm laser illumination, the responsivity reached 0.27 A/W, with a specific detectivity (D*) of 5.1×10⁹ Jones（1 Jones = 1 $\mathrm{cm} \cdot \sqrt{\mathrm{Hz}} / \mathrm{W} $） and an external quantum efficiency (EQE) of 61.6%. Rise/fall times were 8/10 ms for 650 nm illumination and 27/27 ms for 1550 nm illumination. Stability tests under 10 Hz pulsed 532 nm laser cycling for 220 seconds showed no performance degradation. Polarization-sensitive measurements yielded a dichroic ratio of 1.3 at 650 nm.The Sb₂Te₃/ReS₂ van der Waals heterostructure demonstrates exceptional room-temperature photodetection performance across visible to near-infrared wavelengths, coupled with polarization sensitivity. This work highlights the potential of integrating topological insulators with anisotropic 2D materials for multifunctional optoelectronic devices, offering a promising pathway toward advanced broadband and polarization-resolved sensing technologies.