Provided in the present application are an image noise reduction method and device, an imaging system, and a non-transitory computer-readable storage medium. The image noise reduction method includes: processing, based on a first deep learning network, an original scanned object image to acquire a noise image corresponding to the original scanned object image; and acquiring a denoised image based on the original scanned object image and the noise image; wherein the first deep learning network is obtained by training based on low signal-to-noise ratio images and high signal-to-noise ratio images.