The invention discloses a lath cutter comprising a rack, an upper cutter body, a lower cutter body and an elevator mechanism. The upper cutter body is fixedly arranged on the rack, the lower cutter body is arranged under the upper cutter body and can move up and down along the rack, the elevator mechanism drives the lower cutter body to move relative to the upper cutter body to shear a panel, the lath cutter further comprises a balance rod system for balancing the lower cutter body, and the balance rod system comprises left and right cranks and left and right connecting rods. The left and right cranks are symmetrically arranged on both sides of a vertical center of the lower cutter body, and the left and right connecting rods are arranged on both sides of the vertical center. The lower ends of the left and right cranks are both hinged to the rack, the upper ends of the left and right cranks are respectively hinged to the lower ends of the left and right connecting rods, and the upper ends of the left and right connecting rods are hinged to the lower cutter body. The lath cutter enhances the balance and stability of a movable mold by providing the balance rod system and the structure and control are simple and convenient.