The present invention relates to a sheet enabling to form dynamic three-dimensional images and a device for preparing thereof. The sheet comprises a base layer (1), a transparent protective layer (2), a reflective layer (3), and pixel points (4) that can form images. The transparent protective layer (2) is disposed at one side of the base layer (1), the pixel points (4) are embedded in the transparent protective layer (2). The pixel points (4) consist of microlenses (401) tightly closed together. The reflective layer (3) is disposed downbently at a lower part of the microlenses (401), wherein picture-text is recorded in the reflective layer (3). There is an altitude difference H between horizontal positions of two adjacent pixel points (4). Microlenses (401) in any one of pixel point have the same curvature radius, and curvature radius of microlenses (401) in two adjacent pixel points (4) have a difference of 1 to 70 μm.