Abstract: A new automatic online inspecting system for the laser swinger, which is used to measure the tilted error U, the coniform error V, and the compensated error W of the laser swinger, has been developed. The system consists of a autoset level in which its telescope is used, a CCD camera lens, CCD and its assembler, PC computer and a step motor controlled by the computer. The system have the advantage of compact structure, high accuracy with 0.4" and facilities for operation.