The invention relates to a partial discharge detection method based on multi-source image fusion. The partial discharge detection method based on multi-source image fusion is characterized in that S100, an ultrasonic sensor array, a camera, an infrared thermal imager, and an ultraviolet imager are respectively used to acquire ultrasonic wave signals, visible images, infrared images, and ultraviolet images of a detected device synchronously; S 200, the ultrasonic visible images can be acquired based on the acquired ultrasonic wave signals and the visible images; S 300, the ultrasonic visible images, the infrared images, the ultraviolet images can be used as the partial discharge detection result after being fused by adopting the image fusion algorithm, and can be displayed. Compared to the prior art, the partial discharge detection method has advantages of detection precision and high reliability.