The invention discloses a projection objective lens of a photoetching machine, which at least comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventhlens and an eighth lens in sequence from an object plane to an image plane along an optical axis, wherein the object plane side of the first lens is a plane, the image plane side is a convex plane, and the focal power is positive; the object plane side of the second lens is a convex plane, the image plane side is a plane, and the focal power is positive; the object plane side of the third lens isa convex plane, the image plane side is a convex plane, and the focal power is positive; the object plane side of the fourth lens is a plane, the image plane side is a concave plane, and the focal power is negative; the object plane side of the fifth lens is a plane, the image plane side is a convex plane, and the focal power is positive; the object plane side of the sixth lens is a concave plane,the image plane side is a concave plane, and the focal power is negative; the object plane side of the seventh lens is a concave plane, the image plane side is a convex plane, and the focal power ispositive; and the object plane side of the eighth lens is a convex plane, the image plane side is a plane, the focal power is positive. The structure is simple and precision is high.