Small fisheye lens

The utility model relates to the field of fisheye lenses, in particular to a small fisheye lens which sequentially comprises a first lens to a seventh lens from an object side to an image side along an optical axis. Each of the first to seventh lenses comprises an object side surface which faces the object side and allows imaging light to pass through and an image side surface which faces the image side and allows the imaging light to pass through; the first lens has negative diopter, the object side surface is a convex surface, and the image side surface is a concave surface; the second lens has negative diopter, the object side surface is a convex surface, and the image side surface is a concave surface; the third lens has negative diopter, the object side surface is a concave surface, and the image side surface is a convex surface; the fourth lens has positive diopter, the object side surface is a convex surface, and the image side surface is a convex surface; the fifth lens has positive diopter, the objec