The invention relates to the technical field of optical protection films, in particular to an optical film with multiple composite OCA (Optical Clear Adhesive) layers and a preparation method of the optical film. The optical film comprises a first heavy release film, at least two composite OCA layers and a second heavy release film which are adhered to one another in sequence from top to bottom; the composite OCA layers comprise a soft OCA layer and a hard OCA layer which are adhered to each other in sequence from top to bottom. The preparation method comprises the following steps of (1) preparing a composite film A; (2) preparing a composite film B; (3) preparing an optical film having two OCA layers; (4) preparing an optical film having three composite OCA layers; (5) repeating the step (4) to prepare an optical film having more than three composite OCA layers. According to the optical film disclosed by the invention, an edge warping phenomenon of toughened glass when the toughened glass is adhered to a screen can be well solved by appropriately thickening the adhesive layer, and the visual effect is good.