A panel and a manufacturing method thereof are provided. The panel includes a base substrate, and a black matrix layer, a first organic insulating layer and a second organic insulating layer, which are sequentially disposed on the base substrate. The black matrix layer includes a first groove penetrating through the black matrix layer; the first organic insulating layer includes a second groove penetrating through the first organic insulating layer; the second organic insulating layer includes a third groove penetrating through the second organic insulating layer; and the first groove, the second groove and the third groove are interpenetrated with one another.