An optical lens system, from an object side to an imaging surface (S16) thereof, sequentially consisting of: a first lens (L1) having a negative refractive power and a concave surface facing the object side; a second lens (L2) having a positive refractive power and two convex surfaces; a third lens (L3) having a positive refractive power and a convex surface facing the object side; a fourth lens (L4) having a positive refractive power and two convex surfaces; a fifth lens (L5) having a negative refractive power and two concave surfaces, the fourth lens (L4) and the fifth lens (L5) constituting a cemented lens; a sixth lens (L6) having a positive refractive power, a convex surface facing the object side and a concave surface facing the imaging surface (S16); and a seventh lens (L7) having a negative refractive power and a concave surface facing the imaging surface (S16); wherein the optical lens system further comprises a stop (ST) disposed between the first lens (L1) and the third lens (L3), the first lens (L1), the fourth lens (L4) and the fifth lens (L5) are glass spherical lenses, and the seventh lens (L7) is a glass aspheric lens; characterized in that the optical lens system satisfies the following expressions: 0.2 < IH / θ < 0.3 ; 0.5 < f 1 / r 1 < 3 ; 1 < f 3 / r 5 < 4 ; where θ represents half field angle of the optical lens system, IH represents an image height when the half field angle is θ, f 1 represents a focal length of the first lens (L1), r 1 represents a radius of curvature of an object side surface of the first lens (L1), f 3 represents a focal length of the third lens (L3), r 5 represents a radius of curvature of an object side surface of the third lens (L3). a first lens (L1) having a negative refractive power and a concave surface facing the object side; a second lens (L2) having a positive refractive power and two convex surfaces; a third lens (L3) having a positive refractive power and a convex surface facing the object side; a fourth lens (L4) having a positive refractive power and two convex surfaces; a fifth lens (L5) having a negative refractive power and two concave surfaces, the fourth lens (L4) and the fifth lens (L5) constituting a cemented lens; a sixth lens (L6) having a positive refractive power, a convex surface facing the object side and a concave surface facing the imaging surface (S16); and a seventh lens (L7) having a negative refractive power and a concave surface facing the imaging surface (S16); wherein the optical lens system further comprises a stop (ST) disposed between the first lens (L1) and the third lens (L3), the first lens (L1), the fourth lens (L4) and the fifth lens (L5) are glass spherical lenses, and the seventh lens (L7) is a glass aspheric lens; characterized in that the optical lens system satisfies the following expressions: 0.2 < IH / θ < 0.3 ; 0.5 < f 1 / r 1 < 3 ; 1 < f 3 / r 5 < 4 ; where θ represents half field angle of the optical lens system, IH represents an image height when the half field angle is θ, f 1 represents a focal length of the first lens (L1), r 1 represents a radius of curvature of an object side surface of the first lens (L1), f 3 represents a focal length of the third lens (L3), r 5 represents a radius of curvature of an object side surface of the third lens (L3). <EOS>