The present disclosure discloses an imaging lens assembly. The imaging lens assembly includes sequentially from an object side to an image side: a first lens, having a positive refractive power; a second lens, having a negative refractive power, an object-side surface of the second lens being a convex surface, and an image-side surface of the second lens being a concave surface; a third lens, having a positive refractive power, and an image-side surface of the third lens being a convex surface; a fourth lens, having a refractive power; and a fifth lens, having a refractive power, an object-side surface of the fifth lens being a convex surface. An effective focal length f of the imaging lens assembly and an effective focal length f1 of the first lens satisfy: 5.5