The coupling of the tribovoltaic effect and photovoltaic effect (Tribo-Photovoltaic Effect) based on semiconductor dynamic heterojunctions represents an emerging mechanical energy harvesting strategy. Although tribovoltaic nanogenerators (TVNGs) have achieved numerous breakthroughs in the development of new materials and device fabrication, in-depth clarification of their physical mechanisms and promotion to practical applications still require extensive exploration. In this study, high-quality 3C-SiC microcrystalline thin films were successfully prepared via chemical vapor deposition (CVD), and a Cu/3C-SiC dynamic Schottky junction was constructed to enable synergistic harvesting of mechanical energy and ultraviolet light. Compared with commercial 4 H-SiC, the 3C-SiC-based TVNG exhibits higher triboelectric current. Typically, under 360 nm illumination with a power intensity of 2 mW/cm², the output current of the 3C-SiC-based TVNG reaches 18.75 µA, representing a 2.35-times enhancement over the dark environment. Furthermore, by deeply investigating the dominant mechanisms of interfacial and built-in electric fields in the tribovoltaic effect, the theoretical possibility of interfacial electric field existence was verified. This work confirms that CVD-processed 3C-SiC thin films possess significant application potential and broad development prospects in the field of high-performance optoelectronic devices.