Embodiments of the present invention disclose an image synthesis method, an image chip, and an image device. The method includes separately obtaining two coordinates, on a first coordinate axis, corresponding to two boundaries that are of each layer in multiple layers of an image frame and that are perpendicular to the first coordinate axis, so as to obtain multiple coordinates corresponding to the multiple layers. The method also includes dividing, by using the multiple coordinates, the image frame into at least two image segments perpendicular to the first coordinate axis; reading, along a direction of the first coordinate axis, the at least two image segments in a time-division manner and according to a scanning sequence. Additionally, the method includes successively performing image synthesis on the at least two image segments according to a time sequence of reading the at least two image segments, so as to generate display data.