A plastic compound lens for a headlight, comprising: a first lens part adapted to include a first light-incident surface on which light is incident and a first shaped surface through which the light is emitted, and made of a first material; a second lens part adapted to include an inside shaped surface which is coupled onto the first shaped surface, and an outside convex-shaped surface which is formed in a convex shape in a direction opposite the inside shaped surface and which emits the light, incident through the first lens part, to an outside, and made of a second material; and a third lens part coupled onto the first light-incident surface of the first lens, and made of a material identical to or different from that of the second lens part; wherein the first lens part, the second lens part, and the third lens part are integrated with one another, and the second lens part and the third lens part are disposed with the first lens part surrounded by and contained inside the second lens part and the third lens part; wherein the third lens part comprises: a second light-incident surface configured such that light is incident thereon; and a light-incident surface-coupled surface coupled onto the first light-incident surface characterized in that the second lens part extends to the first light-incident surface of the first lens part to surround the first lens part; the first light-incident surface of the first lens part is formed as an aspherical surface including an inflection point; wherein the first shaped surface of the first lens part is formed as an aspherical surface including an inflection point; wherein the inside shaped surface of the second lens part is formed as an aspherical surface including an inflection point to correspond to the first shaped surface of the first lens part; wherein the outside convex-shaped surface of the second lens part is formed as a convex aspherical surface; wherein the second light-incident surface is formed as an aspherical surface including an inflection point; and wherein the light-incident surface-coupled surface is formed as an aspherical surface including an inflection point to correspond to the first light-incident surface of the first lens. a first lens part adapted to include a first light-incident surface on which light is incident and a first shaped surface through which the light is emitted, and made of a first material; a second lens part adapted to include an inside shaped surface which is coupled onto the first shaped surface, and an outside convex-shaped surface which is formed in a convex shape in a direction opposite the inside shaped surface and which emits the light, incident through the first lens part, to an outside, and made of a second material; and a third lens part coupled onto the first light-incident surface of the first lens, and made of a material identical to or different from that of the second lens part; wherein the first lens part, the second lens part, and the third lens part are integrated with one another, and the second lens part and the third lens part are disposed with the first lens part surrounded by and contained inside the second lens part and the third lens part; wherein the third lens part comprises: a second light-incident surface configured such that light is incident thereon; and a light-incident surface-coupled surface coupled onto the first light-incident surface