The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) project has completed its engineering work, and is going to finish commissioning around the end of 2010. The LAMOST telescope is with both large aperture and wide field of view to achieve the large scale spectroscopic survey observation. It is an innovative large aperture meridian active reflecting Schmidt configuration achieved by an active deformable Schmidt mirror, which could not be realized by the traditional optical system. Its primary mirror and active Schmidt mirror are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. A new active optics method succesfully developed in the active deformable Schmidt mirror of LAMOST. It is a conbination of the thin deformable mirror active optics and segmented active optics. This paper presents the optical performance of the telescope of LAMOST during optical test. It is shown that LAMOST project successfully resolving the big technical challenges, and making the progress in active optics and telescope technology.