An optical-lens-set includes a first lens element of positive refractive power, a second lens element of an image surface with a concave portion near the optical-axis, no air gap between a third lens element and a fourth lens element, at least one of an object surface and an image surface of a fifth lens element being aspherical, both an object surface and an image surface of a sixth lens element being aspherical so that the total thickness ALT of all six lens element, the distance TL from an object surface of the first lens element to the image surface of the sixth lens element and total five air gaps AAG satisfy ALT/AAG≤4.5 or TL/AAG≤5.5.