An imaging device, comprising an optical imaging lens and an imaging element, the optical imaging lens from an object side to an image plane on the imaging element along an optical axis of the optical imaging lens, sequentially comprising a first lens, a second lens, a third lens, a stop, a fourth lens, a fifth lens, a sixth lens and a filter; and the stop being arranged between the third lens and the fourth lens; the first lens having a negative refractive power, an object side surface of the first lens being convex, an image side surface of the first lens being concave; the second lens having a negative refractive power, an object side surface of the second lens being convex, an image side surface of the second lens being concave; the third lens having a positive refractive power, an object side surface of the third lens and an image side surface of the third lens being both convex; the fourth lens having a negative refractive power, an object side surface of the fourth lens and an image side surface of the fourth lens being both concave; the fifth lens having a positive refractive power, an object side surface of the fifth lens and an image side surface of the fifth lens being both convex; the fourth lens and the fifth lens forming a cemented lens group; the sixth lens having a positive refractive power, an object side surface of the sixth lens and an image side surface of the sixth lens being both convex; wherein each of the first lens, the second lens, the third lens, the fourth lens and the fifth lens is a glass spherical lens, and the sixth lens is a glass aspherical lens; wherein the optical imaging lens meets the expression: 5.6 < TTL/ImgH < 6.4; where TTL represents a total optical length of the optical imaging lens, and TTL is measured to the imaging element; and ImgH represents a half of the maximum diameter of an effective pixel area on the image plane of the optical imaging lens; and wherein the optical imaging lens is characterised by meeting the expressions: 1.2 < R3/TTL < 2.4; 0.6 < R5/TTL < 1.2; where R3 represents a radius of curvature of the object surface of the second lens, R5 represents a radius of curvature of the object surface of the third lens. the first lens having a negative refractive power, an object side surface of the first lens being convex, an image side surface of the first lens being concave; the second lens having a negative refractive power, an object side surface of the second lens being convex, an image side surface of the second lens being concave; the third lens having a positive refractive power, an object side surface of the third lens and an image side surface of the third lens being both convex; the fourth lens having a negative refractive power, an object side surface of the fourth lens and an image side surface of the fourth lens being both concave; the fifth lens having a positive refractive power, an object side surface of the fifth lens and an image side surface of the fifth lens being both convex; the fourth lens and the fifth lens forming a cemented lens group; the sixth lens having a positive refractive power, an object side surface of the sixth lens and an image side surface of the sixth lens being both convex; wherein each of the first lens, the second lens, the third lens, the fourth lens and the fifth lens is a glass spherical lens, and the sixth lens is a glass aspherical lens; wherein the optical imaging lens meets the expression: 5.6 < TTL/ImgH < 6.4; where TTL represents a total optical length of the optical imaging lens, and TTL is measured to the imaging element; and ImgH represents a half of the maximum diameter of an effective pixel area on the image plane of the optical imaging lens; and wherein the optical imaging lens is characterised by meeting the expressions: 1.2 < R3/TTL < 2.4; 0.6 < R5/TTL < 1.2; where R3 represents a radius of curvature of the object surface of the second lens, R5 represents a radius of curvature of the object surface of the third lens.