The invention provides a display panel and a preparation method thereof, and the display panel forms an organic light-emitting structure layer and a packaging structure layer on a pixel definition layer, and the organic light-emitting structure layer and the packaging structure layer wrap the whole surface of a through hole. According to the invention, the through hole is firstly formed, and thenthe surface of the through hole is coated with the organic light-emitting structure layer and the packaging structure layer, so that the packaging structure layer coats the peripheral side of the through hole, and water vapor is prevented from corroding a metal layer of a display area along the gap between the film layers of the cross section of an open hole.