3D imaging grating assembly and 3D display device

In order to solve a problem that a conventional light-splitting lens has a great thickness so as to be large in size and heavy in weight and unbeneficial to processing and installation, the embodiment of the invention provides a 3D imaging grating assembly and a 3D display device. The 3D imaging grating assembly comprises a light-splitting lens array grating and a collimating lens array grating. The width of each collimating lens is 1/N of the width of a pixel or sub-pixel of a display panel and the width of each light-splitting lens is M times the width of a viewpoint group on the display panel, wherein the N and the M are natural numbers. The 3D imaging grating assembly may decrease the thickness of the light-splitting lens array grating so as to be lower in thickness and weight. Thus, the 3D imaging grating assembly can be directly installed on the surface of the display panel in a full-clinging way, thereby being simplified in installation process. Further, the 3D imaging grating assembly is easy to process and suitable for batch production.