The invention discloses an optical lens and an imaging device. The optical lens sequentially comprises a diaphragm, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lensand a seventh lens from an object side to an imaging surface along an optical axis, wherein the first lens has positive refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative refractive power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens has positive refractive power, and the object side surface of the third lens is a convex surface near the optical axis, and the image side surface of the third lens is a concave surface near the optical axis; the fourth lens has negative refractive power, and the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has positive refractive power, and the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a convex surface; the sixth lens has positive refractive power, and the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a convex surface; and the seventh lens has negative refractive power, and the object side surface of the seventh lens is a concave surface near the optical axis, and the image side surface of the seventhlens is a concave surface near the optical axis. According to the optical lens provided by the invention, by reasonably matching the surface type and refractive power of each lens, the balance of miniaturization and high pixel of the lens can be better realized.