A lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, all of which are arranged in sequence from an object side to an image side along an optical axis. The first lens is a biconvex lens with positive refractive power. The second lens is a meniscus lens with negative refractive power. The third lens is with positive refractive power and includes a convex surface facing the image side. The fourth lens is a meniscus lens with negative refractive power. The fifth lens is a meniscus lens with negative refractive power. The sixth lens is a meniscus lens with positive refractive power.