Embodiments of the present application provide an image fusion apparatus and an image fusion method. The image fusion apparatus includes: a light acquisition device, an image processor, and an image sensor having four types of photosensitive channels. The four types of photosensitive channels include red, green and blue RGB channels and an infrared IR channel. The light acquisition device is configured to filter a spectrum component of a first predetermined wavelength range from incident light to obtain target light. The first predetermined wavelength range is a spectrum wavelength range in which a difference between the responsivities of the RGB channels and the responsivity of the IR channel in the image sensor in the infrared band is higher than a first predetermined threshold. The image sensor is configured to convert the target light into an image signal through the RGB channels and the IR channel. The image processor is configured to analyze the image signal into color signals and a brightness signal that is photosensitive to an infrared band, and perform fusion process on the color signals and the brightness signal to obtain a fused image. With the present solution, the calculation for removing the infrared component from the color signals can be simplified, which improves the efficiency of image fusion.