To address the issue of noise interference in ultraviolet (UV) images, the denoising method based on Facet filtering and local contrast is proposed to enhance image quality for corona detection. First, Facet filtering with a small kernel is applied to the UV image to enhance target pixels and suppress high-intensity noise. Subsequently, a three-layer sliding window traverses the UV image to calculate the local contrast at three levels, generating a saliency map. Finally, noise is removed through threshold segmentation. Experimental results show that proposed method significantly improves UV image quality by enhancing the distinction between salient regions and background, thereby facilitating corona detection.