A multi-focal picture generation apparatus, a head-up display apparatus, a related method, and a device are provided. The multi-focal picture generation apparatus includes a picture generation unit, an optical splitter, and a focal length adjuster. The picture generation unit is configured to generate a first focal plane of the multi-focal picture generation apparatus. The optical splitter is configured to: perform optical splitting on the picture generation unit, and irradiate a light beam obtained through optical splitting onto a surface of the focal length adjuster. The focal length adjuster is configured to perform focal length adjustment on the light beam irradiated onto the surface of the focal length adjuster, to generate a second focal plane of the multi-focal picture generation apparatus.