This invention discloses a method of forming an uneven structure on a substrate. Cut a plurality of trenches in an order on a surface of a mold through a control system, wherein the plurality of trenches comprise at least one first trench, wherein for any second trench of the at least one first trench, the second trench overlaps with at least one third trench different from the second trench such that the second trench is cut off by the at least one third trench. Use the surface of the mold to emboss a thin film on the substrate to form the uneven structure.