Scalable growth of SiC quasi-aligned nanoarrays on SiC wafer substrate was reported through the pyrolysis of polymer precursor by using Au as the catalysts. Differently to the conventional one-dimensional nanostructures often with cylindrical shape, the as-grown SiC nanowires possessed tapered configurations with sharp tips, enabling their desired formation with typical nanoneedle morphology. Their turn-on fields manifested a decline from 3.4 to 1.4 V/μm, when the temperatures were adjusted from room temperature to 400 °C, evidencing their excellent field emission performance. Furthermore, they behaved a high stability with no obvious current emission degradation when subjected to high temperature of 200 °C over 10 h, representing their promising applications in vacuum electronics with robust stability under high-temperature harsh conditions.