While possessing fully superior electrical, optical and mechanical capabilities, the third-generation semiconductor SiC is extensively recognized as one of the most important candidates to developing high-temperature CMOS, intense-radiation hard detectors, high-power electron devices, and other fields. However, the fabrication of low-dimensional SiC structures presents a challenge, limiting its forward-looking applications, particularly for the miniaturized and integrated self-powered ultraviolet (UV) photodetectors. Herein, a high-performance UV photodetector, which involving a p-SiC film, a Ga-doped ZnO microwire coated by Pt nanoparticles (PtNPs@ZnO:Ga MW), a single-layer graphene (Gr) as transparent electrode, was constructed. The device exhibits pronounced UV photodetection capabilities, containing a high On/Off ratio (>105), a peak responsivity approaching 0.266 A/W, a specific detectivity exceeding 1.50 × 1013 Jones, and an exceptional external quantum efficiency closing to 98.7% upon 335 nm illumination at 0 V bias. The detector shows an admirable performance and quite competitive within their class. In the device, the surface-coated PtNPs enable to optimize ZnO:Ga/SiC interfacial performances containing significant enhancement of photoelectric conversion efficiency, efficient suppression of surface/interface defects and trapping centers, and other parameters, thus giving rise to qualitative enhancement of the overall detector properties. Simultaneously, the use of Gr electrode as transparent window allows for maximum UV light absorption and boosts transport properties for the photocarriers. This work presents a valuable reference for the development of high-performance low-dimensional SiC-based photodetecting devices, exploring an important step toward potential optoelectronic applications.